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nuttx/libc/time/lib_localtime.c
Gregory Nutt f087e35676 A little localtime clean-up
2015-04-14 10:46:05 -06:00

2563 lines
64 KiB
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/****************************************************************************
* libc/time/lib_localtime.c
*
* Re-released as part of NuttX under the 3-clause BSD license:
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Ported to NuttX by Max Neklyudov
* Style updates by Gregory Nutt
*
* With these notes:
*
* 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.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <limits.h>
#include <fcntl.h>
#include <errno.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Time zone object file directory */
#ifdef CONFIG_LIBC_TZDIR
# define TZDIR CONFIG_LIBC_TZDIR
#else
# define TZDIR "/etc/zoneinfo"
#endif
/* Time definitions *********************************************************/
/* Time zone files */
#define TZ_MAGIC "TZif"
#define TZDEFAULT "localtime"
#define TZDEFRULES "posixrules"
/* In the current implementation, "tzset()" refuses to deal with files that
* exceed any of the limits below.
*/
#define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */
#define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */
#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)
#define GRANDPARENTED "Local time zone must be set--see zic manual page"
#define TYPE_BIT(type) (sizeof (type) * CHAR_BIT)
#define TYPE_SIGNED(type) (((type) -1) < 0)
#define YEARSPERREPEAT 400 /* years before a Gregorian repeat */
/* The Gregorian year averages 365.2425 days, which is 31556952 seconds. */
#define AVGSECSPERYEAR 31556952L
#define SECSPERREPEAT ((int_fast64_t) YEARSPERREPEAT * (int_fast64_t) AVGSECSPERYEAR)
#define SECSPERREPEAT_BITS 34 /* ceil(log2(SECSPERREPEAT)) */
#define TZ_ABBR_MAX_LEN 16
#define TZ_ABBR_CHAR_SET \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
#define TZ_ABBR_ERR_CHAR '_'
/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */
#define is_digit(c) ((unsigned)(c) - '0' <= 9)
#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b))
#define MY_TZNAME_MAX 255
#define GMT "GMT"
#define GMTLEN 3
#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 */
/* 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.
*
* 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 " "
/* The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
* We default to US rules as of 1999-08-17.
* POSIX 1003.1 section 8.1.1 says that the default DST rules are
* implementation dependent; for historical reasons, US rules are a
* common default.
*/
#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
/****************************************************************************
* Private Types
****************************************************************************/
/* Time file file header.
* Each time zone file begins with a time zone header followed by:
*
* tzh_timecnt (char [4])s coded transition times a la time(2)
* tzh_timecnt (unsigned char)s types of local time starting at above
* tzh_typecnt repetitions of
* one (char [4]) coded UT offset in seconds
* one (unsigned char) used to set tm_isdst
* one (unsigned char) that's an abbreviation list index
* tzh_charcnt (char)s '\0'-terminated zone abbreviations
* tzh_leapcnt repetitions of
* one (char [4]) coded leap second transition times
* one (char [4]) total correction after above
* tzh_ttisstdcnt (char)s indexed by type; if TRUE, transition
* time is standard time, if FALSE,
* transition time is wall clock time
* if absent, transition times are
* assumed to be wall clock time
* tzh_ttisgmtcnt (char)s indexed by type; if TRUE, transition
* time is UT, if FALSE,
* transition time is local time
* if absent, transition times are
* assumed to be local time
*
* If tzh_version is '2' or greater, the above is followed by a second
* instance of tzhead_s and a second instance of the data in which each
* coded transition time uses 8 rather than 4 chars, then a
* POSIX-TZ-environment-variable-style string for use in handling instants
* after the last transition time stored in the file (with nothing between
* the newlines if there is no POSIX representation for such instants).
*
* If tz_version is '3' or greater, the above is extended as follows.
* First, the POSIX TZ string's hour offset may range from -167 through
* 167 as compared to the POSIX-required 0 through 24. Second, its DST
* start time may be January 1 at 00:00 and its stop time December 31 at
* 24:00 plus the difference between DST and standard time, indicating DST
* all year.
*/
struct tzhead_s
{
char tzh_magic[4]; /* TZ_MAGIC */
char tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */
char tzh_reserved[15]; /* reserved; must be zero */
char tzh_ttisgmtcnt[4]; /* coded number of trans. time flags */
char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */
char tzh_leapcnt[4]; /* coded number of leap seconds */
char tzh_timecnt[4]; /* coded number of transition times */
char tzh_typecnt[4]; /* coded number of local time types */
char tzh_charcnt[4]; /* coded number of abbr. chars */
};
struct ttinfo_s
{ /* 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_s
{ /* Leap second information */
time_t ls_trans; /* Transition time */
int_fast64_t ls_corr; /* Correction to apply */
};
struct state_s
{
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_s ttis[TZ_MAX_TYPES];
char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, GMTLEN), (2 * (MY_TZNAME_MAX + 1)))];
struct lsinfo_s lsis[TZ_MAX_LEAPS];
int defaulttype; /* For early times or if no transitions */
};
struct rule_s
{
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 */
};
/****************************************************************************
* Private Data
****************************************************************************/
/* The minimum and maximum finite time values. */
static time_t const g_min_timet =
(TYPE_SIGNED(time_t)
? (time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1)
: 0);
static time_t const g_max_timet =
(TYPE_SIGNED(time_t)
? - (~ 0 < 0) - ((time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1))
: -1);
static const char g_wildabbr[] = WILDABBR;
static char g_lcl_tzname[MY_TZNAME_MAX + 1];
static int g_lcl_isset;
static int g_gmt_isset;
/* Section 4.12.3 of X3.159-1989 requires that
* Except for the strftime function, these functions [asctime,
* ctime, gmtime, localtime] return values in one of two static
* objects: a broken-down time structure and an array of char.
* Thanks to Paul Eggert for noting this.
*/
static struct tm g_tm;
static const int g_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 g_year_lengths[2] =
{
DAYSPERNYEAR, DAYSPERLYEAR
};
/****************************************************************************
* Public Data
****************************************************************************/
/* Setup by tzset() */
FAR char *tzname[2] =
{
(FAR char *)g_wildabbr,
(FAR char *)g_wildabbr
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int_fast32_t detzcode(FAR const char *codep);
static int_fast64_t detzcode64(FAR const char *codep);
static int differ_by_repeat(time_t t1, time_t t0);
static FAR const char *getzname(FAR const char *strp);
static FAR const char *getqzname(FAR const char *strp, const int delim);
static FAR const char *getnum(FAR const char *strp, FAR int *nump,
int min, int max);
static FAR const char *getsecs(FAR const char *strp, FAR int_fast32_t *secsp);
static FAR const char *getoffset(FAR const char *strp,
FAR int_fast32_t *offsetp);
static FAR const char *getrule(FAR const char *strp,
FAR struct rule_s *rulep);
static void gmtload(struct state_s *sp);
static FAR struct tm *gmtsub(FAR const time_t * timep, int_fast32_t offset,
FAR struct tm *tmp);
static FAR struct tm *localsub(FAR const time_t * timep, int_fast32_t offset,
FAR struct tm *tmp);
static int increment_overflow(FAR int *number, int delta);
static int leaps_thru_end_of(int y);
static int increment_overflow32(FAR int_fast32_t * number, int delta);
static int increment_overflow_time(time_t * t, int_fast32_t delta);
static int normalize_overflow32(FAR int_fast32_t * tensptr,
FAR int *unitsptr, int base);
static int normalize_overflow(FAR int *tensptr, FAR int *unitsptr, int base);
static void settzname(void);
static time_t time1(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t,
FAR struct tm *),
int_fast32_t offset);
static time_t time2(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
int_fast32_t offset, FAR int *okayp);
static time_t time2sub(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
int_fast32_t offset, FAR int *okayp, int do_norm_secs);
static FAR struct tm *timesub(FAR const time_t * timep, int_fast32_t offset,
FAR const struct state_s *sp, FAR struct tm *tmp);
static int tmcomp(FAR const struct tm *atmp, FAR const struct tm *btmp);
static int_fast32_t transtime(int year, FAR const struct rule_s *rulep,
int_fast32_t offset);
static int typesequiv(FAR const struct state_s *sp, int a, int b);
static int tzload(FAR const char *name, FAR struct state_s *sp,
int doextend);
static int tzparse(FAR const char *name, FAR struct state_s *sp,
int lastditch);
static FAR struct state_s *lclptr;
static FAR struct state_s *gmtptr;
/****************************************************************************
* Private Functions
****************************************************************************/
static int_fast32_t detzcode(FAR const char *const codep)
{
int_fast32_t result;
int i;
result = (codep[0] & 0x80) ? -1 : 0;
for (i = 0; i < 4; ++i)
{
result = (result << 8) | (codep[i] & 0xff);
}
return result;
}
static int_fast64_t detzcode64(FAR const char *const codep)
{
int_fast64_t result;
int i;
result = (codep[0] & 0x80) ? -1 : 0;
for (i = 0; i < 8; ++i)
{
result = (result << 8) | (codep[i] & 0xff);
}
return result;
}
static void settzname(void)
{
FAR struct state_s *const sp = lclptr;
int i;
tzname[0] = tzname[1] = (FAR char*)g_wildabbr;
if (sp == NULL)
{
tzname[0] = tzname[1] = (FAR char*)GMT;
return;
}
/* And to get the latest zone names into tzname */
for (i = 0; i < sp->typecnt; ++i)
{
const struct ttinfo_s *const ttisp = &sp->ttis[i];
tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind];
}
for (i = 0; i < sp->timecnt; ++i)
{
const struct ttinfo_s *const ttisp = &sp->ttis[sp->types[i]];
tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind];
}
/* Finally, scrub the abbreviations. First, replace bogus characters. */
for (i = 0; i < sp->charcnt; ++i)
{
if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
{
sp->chars[i] = TZ_ABBR_ERR_CHAR;
}
}
/* Second, truncate long abbreviations. */
for (i = 0; i < sp->typecnt; ++i)
{
const struct ttinfo_s *const ttisp = &sp->ttis[i];
char *cp = &sp->chars[ttisp->tt_abbrind];
if (strlen(cp) > TZ_ABBR_MAX_LEN && strcmp(cp, GRANDPARENTED) != 0)
{
*(cp + TZ_ABBR_MAX_LEN) = '\0';
}
}
}
static int differ_by_repeat(const time_t t1, const time_t t0)
{
if (TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
{
return 0;
}
return t1 - t0 == SECSPERREPEAT;
}
static int tzload(FAR const char *name,
FAR struct state_s *const sp, const int doextend)
{
FAR const char *p;
int i;
int fid;
int stored;
int nread;
typedef union
{
struct tzhead_s tzhead_s;
char buf[2 * sizeof(struct tzhead_s) + 2 * sizeof *sp + 4 * TZ_MAX_TIMES];
} u_t;
union local_storage
{
/* Section 4.9.1 of the C standard says that
* "FILENAME_MAX expands to an integral constant expression
* that is the size needed for an array of char large enough
* to hold the longest file name string that the implementation
* guarantees can be opened."
*/
char fullname[FILENAME_MAX + 1];
/* The main part of the storage for this function. */
struct
{
u_t u;
struct state_s st;
} u;
};
char *fullname;
u_t *up;
int doaccess;
union local_storage *lsp;
lsp = malloc(sizeof *lsp);
if (!lsp)
{
return -1;
}
fullname = lsp->fullname;
up = &lsp->u.u;
sp->goback = sp->goahead = FALSE;
if (!name)
{
name = TZDEFAULT;
if (!name)
{
goto oops;
}
}
if (name[0] == ':')
{
++name;
}
doaccess = name[0] == '/';
if (!doaccess)
{
p = TZDIR;
if (!p || sizeof lsp->fullname - 1 <= strlen(p) + strlen(name))
{
goto oops;
}
strcpy(fullname, p);
strcat(fullname, "/");
strcat(fullname, name);
/* Set doaccess if '.' (as in "../") shows up in name. */
if (strchr(name, '.'))
{
doaccess = TRUE;
}
name = fullname;
}
if (doaccess && access(name, R_OK) != 0)
{
goto oops;
}
fid = open(name, O_RDONLY | O_BINARY);
if (fid < 0)
{
goto oops;
}
nread = read(fid, up->buf, sizeof up->buf);
if (close(fid) < 0 || nread <= 0)
{
goto oops;
}
for (stored = 4; stored <= 8; stored *= 2)
{
int ttisstdcnt;
int ttisgmtcnt;
int timecnt;
ttisstdcnt = (int)detzcode(up->tzhead_s.tzh_ttisstdcnt);
ttisgmtcnt = (int)detzcode(up->tzhead_s.tzh_ttisgmtcnt);
sp->leapcnt = (int)detzcode(up->tzhead_s.tzh_leapcnt);
sp->timecnt = (int)detzcode(up->tzhead_s.tzh_timecnt);
sp->typecnt = (int)detzcode(up->tzhead_s.tzh_typecnt);
sp->charcnt = (int)detzcode(up->tzhead_s.tzh_charcnt);
p = up->tzhead_s.tzh_charcnt + sizeof up->tzhead_s.tzh_charcnt;
if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
{
goto oops;
}
if (nread - (p - up->buf) < sp->timecnt * stored + /* ats */
sp->timecnt + /* types */
sp->typecnt * 6 + /* ttinfos */
sp->charcnt + /* chars */
sp->leapcnt * (stored + 4) + /* lsinfos */
ttisstdcnt + /* ttisstds */
ttisgmtcnt) /* ttisgmts */
{
goto oops;
}
timecnt = 0;
for (i = 0; i < sp->timecnt; ++i)
{
int_fast64_t at = stored == 4 ? detzcode(p) : detzcode64(p);
sp->types[i] = ((TYPE_SIGNED(time_t)
? g_min_timet <= at : 0 <= at) && at <= g_max_timet);
if (sp->types[i])
{
if (i && !timecnt && at != g_min_timet)
{
/* Keep the earlier record, but tweak
* it so that it starts with the
* minimum time_t value.
*/
sp->types[i - 1] = 1;
sp->ats[timecnt++] = g_min_timet;
}
sp->ats[timecnt++] = at;
}
p += stored;
}
timecnt = 0;
for (i = 0; i < sp->timecnt; ++i)
{
unsigned char typ = *p++;
if (sp->typecnt <= typ)
{
goto oops;
}
if (sp->types[i])
{
sp->types[timecnt++] = typ;
}
}
sp->timecnt = timecnt;
for (i = 0; i < sp->typecnt; ++i)
{
struct ttinfo_s *ttisp;
ttisp = &sp->ttis[i];
ttisp->tt_gmtoff = detzcode(p);
p += 4;
ttisp->tt_isdst = (unsigned char)*p++;
if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
{
goto oops;
}
ttisp->tt_abbrind = (unsigned char)*p++;
if (ttisp->tt_abbrind < 0 || ttisp->tt_abbrind > sp->charcnt)
{
goto oops;
}
}
for (i = 0; i < sp->charcnt; ++i)
{
sp->chars[i] = *p++;
}
sp->chars[i] = '\0'; /* ensure '\0' at end */
for (i = 0; i < sp->leapcnt; ++i)
{
struct lsinfo_s *lsisp;
lsisp = &sp->lsis[i];
lsisp->ls_trans = (stored == 4) ? detzcode(p) : detzcode64(p);
p += stored;
lsisp->ls_corr = detzcode(p);
p += 4;
}
for (i = 0; i < sp->typecnt; ++i)
{
struct ttinfo_s *ttisp;
ttisp = &sp->ttis[i];
if (ttisstdcnt == 0)
{
ttisp->tt_ttisstd = FALSE;
}
else
{
ttisp->tt_ttisstd = *p++;
if (ttisp->tt_ttisstd != TRUE && ttisp->tt_ttisstd != FALSE)
{
goto oops;
}
}
}
for (i = 0; i < sp->typecnt; ++i)
{
struct ttinfo_s *ttisp;
ttisp = &sp->ttis[i];
if (ttisgmtcnt == 0)
{
ttisp->tt_ttisgmt = FALSE;
}
else
{
ttisp->tt_ttisgmt = *p++;
if (ttisp->tt_ttisgmt != TRUE && ttisp->tt_ttisgmt != FALSE)
{
goto oops;
}
}
}
/* If this is an old file, we're done. */
if (up->tzhead_s.tzh_version[0] == '\0')
{
break;
}
nread -= p - up->buf;
for (i = 0; i < nread; ++i)
{
up->buf[i] = p[i];
}
/* If this is a signed narrow time_t system, we're done. */
if (TYPE_SIGNED(time_t) && stored >= (int)sizeof(time_t))
{
break;
}
}
if (doextend && nread > 2 &&
up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
sp->typecnt + 2 <= TZ_MAX_TYPES)
{
FAR struct state_s *ts = &lsp->u.st;
int result;
up->buf[nread - 1] = '\0';
result = tzparse(&up->buf[1], ts, FALSE);
if (result == 0 && ts->typecnt == 2 &&
sp->charcnt + ts->charcnt <= TZ_MAX_CHARS)
{
for (i = 0; i < 2; ++i)
{
ts->ttis[i].tt_abbrind += sp->charcnt;
}
for (i = 0; i < ts->charcnt; ++i)
{
sp->chars[sp->charcnt++] = ts->chars[i];
}
i = 0;
while (i < ts->timecnt && ts->ats[i] <= sp->ats[sp->timecnt - 1])
{
++i;
}
while (i < ts->timecnt && sp->timecnt < TZ_MAX_TIMES)
{
sp->ats[sp->timecnt] = ts->ats[i];
sp->types[sp->timecnt] = sp->typecnt + ts->types[i];
++sp->timecnt;
++i;
}
sp->ttis[sp->typecnt++] = ts->ttis[0];
sp->ttis[sp->typecnt++] = ts->ttis[1];
}
}
if (sp->timecnt > 1)
{
for (i = 1; i < sp->timecnt; ++i)
{
if (typesequiv(sp, sp->types[i], sp->types[0]) &&
differ_by_repeat(sp->ats[i], sp->ats[0]))
{
sp->goback = TRUE;
break;
}
}
for (i = sp->timecnt - 2; i >= 0; --i)
{
if (typesequiv(sp, sp->types[sp->timecnt - 1],
sp->types[i]) &&
differ_by_repeat(sp->ats[sp->timecnt - 1], sp->ats[i]))
{
sp->goahead = TRUE;
break;
}
}
}
/* If type 0 is is unused in transitions, it's the type to use for early
* times.
*/
for (i = 0; i < sp->typecnt; ++i)
{
if (sp->types[i] == 0)
{
break;
}
}
i = (i >= sp->typecnt) ? 0 : -1;
/* Absent the above, if there are transition times and the first
* transition is to a daylight time find the standard type less than and
* closest to the type of the first transition.
*/
if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst)
{
i = sp->types[0];
while (--i >= 0)
{
if (!sp->ttis[i].tt_isdst)
{
break;
}
}
}
/* If no result yet, find the first standard type. If there is none, punt
* to type zero.
*/
if (i < 0)
{
i = 0;
while (sp->ttis[i].tt_isdst)
{
if (++i >= sp->typecnt)
{
i = 0;
break;
}
}
}
sp->defaulttype = i;
free(up);
return 0;
oops:
free(up);
return -1;
}
static int typesequiv(FAR const struct state_s *const sp, const int a, const int b)
{
int result;
if (sp == NULL || a < 0 || a >= sp->typecnt || b < 0 || b >= sp->typecnt)
{
result = FALSE;
}
else
{
const struct ttinfo_s *ap = &sp->ttis[a];
const struct ttinfo_s *bp = &sp->ttis[b];
result = ap->tt_gmtoff == bp->tt_gmtoff &&
ap->tt_isdst == bp->tt_isdst &&
ap->tt_ttisstd == bp->tt_ttisstd &&
ap->tt_ttisgmt == bp->tt_ttisgmt &&
strcmp(&sp->chars[ap->tt_abbrind], &sp->chars[bp->tt_abbrind]) == 0;
}
return result;
}
/* Given a pointer into a time zone string, scan until a character that is not
* a valid character in a zone name is found. Return a pointer to that
* character.
*/
static FAR const char *getzname(FAR const char *strp)
{
char c;
while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && c != '+')
{
++strp;
}
return strp;
}
/* Given a pointer into an extended time zone string, scan until the ending
* delimiter of the zone name is located. Return a pointer to the delimiter.
*
* As with getzname above, the legal character set is actually quite
* restricted, with other characters producing undefined results.
* We don't do any checking here; checking is done later in common-case code.
*/
static FAR const char *getqzname(FAR const char *strp, const int delim)
{
int c;
while ((c = *strp) != '\0' && c != delim)
{
++strp;
}
return strp;
}
/* Given a pointer into a time zone string, extract a number from that string.
* Check that the number is within a specified range; if it is not, return
* NULL.
* Otherwise, return a pointer to the first character not part of the number.
*/
static FAR const char *getnum(FAR const char *strp, FAR int *const nump,
const int min, const int max)
{
char c;
int num;
if (strp == NULL || !is_digit(c = *strp))
{
return NULL;
}
num = 0;
do
{
num = num * 10 + (c - '0');
if (num > max)
{
return NULL; /* illegal value */
}
c = *++strp;
}
while (is_digit(c));
if (num < min)
{
return NULL; /* illegal value */
}
*nump = num;
return strp;
}
/* Given a pointer into a time zone string, extract a number of seconds,
* in hh[:mm[:ss]] form, from the string.
* If any error occurs, return NULL.
* Otherwise, return a pointer to the first character not part of the number
* of seconds.
*/
static FAR const char *getsecs(FAR const char *strp,
FAR int_fast32_t * const secsp)
{
int num;
/* 'HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
* "M10.4.6/26", which does not conform to Posix,
* but which specifies the equivalent of
* "02:00 on the first Sunday on or after 23 Oct".
*/
strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
if (strp == NULL)
{
return NULL;
}
*secsp = num * (int_fast32_t) SECSPERHOUR;
if (*strp == ':')
{
++strp;
strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
if (strp == NULL)
{
return NULL;
}
*secsp += num * SECSPERMIN;
if (*strp == ':')
{
++strp;
/* 'SECSPERMIN' allows for leap seconds. */
strp = getnum(strp, &num, 0, SECSPERMIN);
if (strp == NULL)
{
return NULL;
}
*secsp += num;
}
}
return strp;
}
/* Given a pointer into a time zone string, extract an offset, in
* [+-]hh[:mm[:ss]] form, from the string.
* If any error occurs, return NULL.
* Otherwise, return a pointer to the first character not part of the time.
*/
static FAR const char *getoffset(FAR const char *strp,
FAR int_fast32_t * const offsetp)
{
int neg = 0;
if (*strp == '-')
{
neg = 1;
++strp;
}
else if (*strp == '+')
{
++strp;
}
strp = getsecs(strp, offsetp);
if (strp == NULL)
{
return NULL; /* illegal time */
}
if (neg)
{
*offsetp = -*offsetp;
}
return strp;
}
/* Given a pointer into a time zone string, extract a rule in the form
* date[/time]. See POSIX section 8 for the format of "date" and "time".
* If a valid rule is not found, return NULL.
* Otherwise, return a pointer to the first character not part of the rule.
*/
static FAR const char *getrule(FAR const char *strp,
FAR struct rule_s *const rulep)
{
if (*strp == 'J')
{
/* Julian day */
rulep->r_type = JULIAN_DAY;
++strp;
strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
}
else if (*strp == 'M')
{
/* Month, week, day. */
rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
++strp;
strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
if (strp == NULL)
{
return NULL;
}
if (*strp++ != '.')
{
return NULL;
}
strp = getnum(strp, &rulep->r_week, 1, 5);
if (strp == NULL)
{
return NULL;
}
if (*strp++ != '.')
{
return NULL;
}
strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
}
else if (is_digit(*strp))
{
/* Day of year */
rulep->r_type = DAY_OF_YEAR;
strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
}
else
{
return NULL; /* invalid format */
}
if (strp == NULL)
{
return NULL;
}
if (*strp == '/')
{
/* Time specified */
++strp;
strp = getoffset(strp, &rulep->r_time);
}
else
{
rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
}
return strp;
}
/*Given a year, a rule, and the offset from UT at the time that rule takes
* effect, calculate the year-relative time that rule takes effect.
*/
static int_fast32_t transtime(const int year,
FAR const struct rule_s *const rulep,
const int_fast32_t offset)
{
int leapyear;
int_fast32_t value;
int i;
int d, m1, yy0, yy1, yy2, dow;
value = 0;
leapyear = isleap(year);
switch (rulep->r_type)
{
case JULIAN_DAY:
/* Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
* years.
* In non-leap years, or if the day number is 59 or less, just
* add SECSPERDAY times the day number-1 to the time of
* January 1, midnight, to get the day.
*/
value = (rulep->r_day - 1) * SECSPERDAY;
if (leapyear && rulep->r_day >= 60)
value += SECSPERDAY;
break;
case DAY_OF_YEAR:
/* n - day of year.
* Just add SECSPERDAY times the day number to the time of
* January 1, midnight, to get the day.
*/
value = rulep->r_day * SECSPERDAY;
break;
case MONTH_NTH_DAY_OF_WEEK:
/* Mm.n.d - nth "dth day" of month m */
/* Use Zeller's Congruence to get day-of-week of first day of
* month.
*/
m1 = (rulep->r_mon + 9) % 12 + 1;
yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
yy1 = yy0 / 100;
yy2 = yy0 % 100;
dow = ((26 * m1 - 2) / 10 + 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
if (dow < 0)
{
dow += DAYSPERWEEK;
}
/* "dow" is the day-of-week of the first day of the month. Get
* the day-of-month (zero-origin) of the first "dow" day of the
* month.
*/
d = rulep->r_day - dow;
if (d < 0)
{
d += DAYSPERWEEK;
}
for (i = 1; i < rulep->r_week; ++i)
{
if (d + DAYSPERWEEK >= g_mon_lengths[leapyear][rulep->r_mon - 1])
{
break;
}
d += DAYSPERWEEK;
}
/* "d" is the day-of-month (zero-origin) of the day we want */
value = d * SECSPERDAY;
for (i = 0; i < rulep->r_mon - 1; ++i)
{
value += g_mon_lengths[leapyear][i] * SECSPERDAY;
}
break;
}
/* "value" is the year-relative time of 00:00:00 UT on the day in
* question. To get the year-relative time of the specified local
* time on that day, add the transition time and the current offset
* from UT.
*/
return value + rulep->r_time + offset;
}
/* Given a POSIX section 8-style TZ string, fill in the rule tables as
* appropriate.
*/
static int tzparse(FAR const char *name, FAR struct state_s *const sp,
const int lastditch)
{
FAR const char *stdname;
FAR const char *dstname;
size_t stdlen;
size_t dstlen;
int_fast32_t stdoffset;
int_fast32_t dstoffset;
char *cp;
int load_result;
static struct ttinfo_s zttinfo;
stdname = name;
if (lastditch)
{
stdlen = strlen(name); /* length of standard zone name */
name += stdlen;
if (stdlen >= sizeof sp->chars)
{
stdlen = (sizeof sp->chars) - 1;
}
stdoffset = 0;
}
else
{
if (*name == '<')
{
name++;
stdname = name;
name = getqzname(name, '>');
if (*name != '>')
{
return -1;
}
stdlen = name - stdname;
name++;
}
else
{
name = getzname(name);
stdlen = name - stdname;
}
if (*name == '\0')
{
return -1;
}
name = getoffset(name, &stdoffset);
if (name == NULL)
{
return -1;
}
}
load_result = tzload(TZDEFRULES, sp, FALSE);
if (load_result != 0)
{
sp->leapcnt = 0; /* so, we're off a little */
}
if (*name != '\0')
{
if (*name == '<')
{
dstname = ++name;
name = getqzname(name, '>');
if (*name != '>')
{
return -1;
}
dstlen = name - dstname;
name++;
}
else
{
dstname = name;
name = getzname(name);
dstlen = name - dstname; /* length of DST zone name */
}
if (*name != '\0' && *name != ',' && *name != ';')
{
name = getoffset(name, &dstoffset);
if (name == NULL)
{
return -1;
}
}
else
{
dstoffset = stdoffset - SECSPERHOUR;
}
if (*name == '\0' && load_result != 0)
{
name = TZDEFRULESTRING;
}
if (*name == ',' || *name == ';')
{
struct rule_s start;
struct rule_s end;
int year;
int yearlim;
int timecnt;
time_t janfirst;
++name;
if ((name = getrule(name, &start)) == NULL)
{
return -1;
}
if (*name++ != ',')
{
return -1;
}
if ((name = getrule(name, &end)) == NULL)
{
return -1;
}
if (*name != '\0')
{
return -1;
}
sp->typecnt = 2; /* standard time and DST */
/* Two transitions per year, from EPOCH_YEAR forward */
sp->ttis[0] = sp->ttis[1] = zttinfo;
sp->ttis[0].tt_gmtoff = -dstoffset;
sp->ttis[0].tt_isdst = 1;
sp->ttis[0].tt_abbrind = stdlen + 1;
sp->ttis[1].tt_gmtoff = -stdoffset;
sp->ttis[1].tt_isdst = 0;
sp->ttis[1].tt_abbrind = 0;
sp->defaulttype = 0;
timecnt = 0;
janfirst = 0;
yearlim = EPOCH_YEAR + YEARSPERREPEAT;
for (year = EPOCH_YEAR; year < yearlim; year++)
{
int_fast32_t
starttime = transtime(year, &start, stdoffset),
endtime = transtime(year, &end, dstoffset);
int_fast32_t yearsecs = (g_year_lengths[isleap(year)] * SECSPERDAY);
int reversed = endtime < starttime;
if (reversed)
{
int_fast32_t swap = starttime;
starttime = endtime;
endtime = swap;
}
if (reversed ||
(starttime < endtime &&
(endtime - starttime < (yearsecs + (stdoffset - dstoffset)))))
{
if (TZ_MAX_TIMES - 2 < timecnt)
{
break;
}
yearlim = year + YEARSPERREPEAT + 1;
sp->ats[timecnt] = janfirst;
if (increment_overflow_time(&sp->ats[timecnt], starttime))
{
break;
}
sp->types[timecnt++] = reversed;
sp->ats[timecnt] = janfirst;
if (increment_overflow_time(&sp->ats[timecnt], endtime))
{
break;
}
sp->types[timecnt++] = !reversed;
}
if (increment_overflow_time(&janfirst, yearsecs))
{
break;
}
}
sp->timecnt = timecnt;
if (!timecnt)
{
sp->typecnt = 1; /* Perpetual DST. */
}
}
else
{
int_fast32_t theirstdoffset;
int_fast32_t theirdstoffset;
int_fast32_t theiroffset;
int isdst;
int i;
int j;
if (*name != '\0')
{
return -1;
}
/* Initial values of theirstdoffset and theirdstoffset */
theirstdoffset = 0;
for (i = 0; i < sp->timecnt; ++i)
{
j = sp->types[i];
if (!sp->ttis[j].tt_isdst)
{
theirstdoffset = -sp->ttis[j].tt_gmtoff;
break;
}
}
theirdstoffset = 0;
for (i = 0; i < sp->timecnt; ++i)
{
j = sp->types[i];
if (sp->ttis[j].tt_isdst)
{
theirdstoffset = -sp->ttis[j].tt_gmtoff;
break;
}
}
/* Initially we're assumed to be in standard time */
isdst = FALSE;
theiroffset = theirstdoffset;
/* Now juggle transition times and types
* tracking offsets as you do.
*/
for (i = 0; i < sp->timecnt; ++i)
{
j = sp->types[i];
sp->types[i] = sp->ttis[j].tt_isdst;
if (sp->ttis[j].tt_ttisgmt)
{
/* No adjustment to transition time */
}
else
{
/* If summer time is in effect, and the
* transition time was not specified as
* standard time, add the summer time
* offset to the transition time;
* otherwise, add the standard time
* offset to the transition time.
*
* Transitions from DST to DDST
* will effectively disappear since
* POSIX provides for only one DST
* offset.
*/
if (isdst && !sp->ttis[j].tt_ttisstd)
{
sp->ats[i] += dstoffset - theirdstoffset;
}
else
{
sp->ats[i] += stdoffset - theirstdoffset;
}
}
theiroffset = -sp->ttis[j].tt_gmtoff;
if (sp->ttis[j].tt_isdst)
{
theirdstoffset = theiroffset;
}
else
{
theirstdoffset = theiroffset;
}
}
/* Finally, fill in ttis */
sp->ttis[0] = sp->ttis[1] = zttinfo;
sp->ttis[0].tt_gmtoff = -stdoffset;
sp->ttis[0].tt_isdst = FALSE;
sp->ttis[0].tt_abbrind = 0;
sp->ttis[1].tt_gmtoff = -dstoffset;
sp->ttis[1].tt_isdst = TRUE;
sp->ttis[1].tt_abbrind = stdlen + 1;
sp->typecnt = 2;
sp->defaulttype = 0;
}
}
else
{
dstlen = 0;
sp->typecnt = 1; /* only standard time */
sp->timecnt = 0;
sp->ttis[0] = zttinfo;
sp->ttis[0].tt_gmtoff = -stdoffset;
sp->ttis[0].tt_isdst = 0;
sp->ttis[0].tt_abbrind = 0;
sp->defaulttype = 0;
}
sp->charcnt = stdlen + 1;
if (dstlen != 0)
{
sp->charcnt += dstlen + 1;
}
if ((size_t) sp->charcnt > sizeof sp->chars)
{
return -1;
}
cp = sp->chars;
(void)strncpy(cp, stdname, stdlen);
cp += stdlen;
*cp++ = '\0';
if (dstlen != 0)
{
(void)strncpy(cp, dstname, dstlen);
*(cp + dstlen) = '\0';
}
return 0;
}
static void gmtload(FAR struct state_s *const sp)
{
if (tzload(GMT, sp, TRUE) != 0)
{
(void)tzparse(GMT, sp, TRUE);
}
}
/* A non-static declaration of tzsetwall in a system header file
* may cause a warning about this upcoming static declaration...
*/
static void tzsetwall(void)
{
if (g_lcl_isset < 0)
{
return;
}
g_lcl_isset = -1;
if (lclptr == NULL)
{
lclptr = malloc(sizeof *lclptr);
if (lclptr == NULL)
{
settzname(); /* all we can do */
return;
}
}
if (tzload(NULL, lclptr, TRUE) != 0)
{
gmtload(lclptr);
}
settzname();
}
/* The easy way to behave "as if no library function calls" localtime
* is to not call it, so we drop its guts into "localsub", which can be
* freely called. (And no, the PANS doesn't require the above behavior,
* but it *is* desirable.)
*
* The unused offset argument is for the benefit of mktime variants.
*/
static struct tm *localsub(FAR const time_t * const timep,
const int_fast32_t offset, struct tm *const tmp)
{
FAR struct state_s *sp;
const struct ttinfo_s *ttisp;
int i;
struct tm *result;
const time_t t = *timep;
sp = lclptr;
if (sp == NULL)
{
return gmtsub(timep, offset, tmp);
}
if ((sp->goback && t < sp->ats[0]) ||
(sp->goahead && t > sp->ats[sp->timecnt - 1]))
{
time_t newt = t;
time_t seconds;
time_t years;
if (t < sp->ats[0])
{
seconds = sp->ats[0] - t;
}
else
{
seconds = t - sp->ats[sp->timecnt - 1];
}
--seconds;
years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT;
seconds = years * AVGSECSPERYEAR;
if (t < sp->ats[0])
{
newt += seconds;
}
else
{
newt -= seconds;
}
if (newt < sp->ats[0] || newt > sp->ats[sp->timecnt - 1])
{
return NULL; /* "cannot happen" */
}
result = localsub(&newt, offset, tmp);
if (result == tmp)
{
time_t newy;
newy = tmp->tm_year;
if (t < sp->ats[0])
{
newy -= years;
}
else
{
newy += years;
}
tmp->tm_year = newy;
if (tmp->tm_year != newy)
{
return NULL;
}
}
return result;
}
if (sp->timecnt == 0 || t < sp->ats[0])
{
i = sp->defaulttype;
}
else
{
int lo = 1;
int hi = sp->timecnt;
while (lo < hi)
{
int mid = (lo + hi) >> 1;
if (t < sp->ats[mid])
{
hi = mid;
}
else
{
lo = mid + 1;
}
}
i = (int)sp->types[lo - 1];
}
ttisp = &sp->ttis[i];
/* To get (wrong) behavior that's compatible with System V Release 2.0
* you'd replace the statement below with
* t += ttisp->tt_gmtoff;
* timesub(&t, 0L, sp, tmp);
*/
result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
tmp->tm_isdst = ttisp->tt_isdst;
tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
return result;
}
/* gmtsub is to gmtime as localsub is to localtime */
static struct tm *gmtsub(FAR const time_t * const timep, const int_fast32_t offset,
struct tm *const tmp)
{
if (!g_gmt_isset)
{
gmtptr = malloc(sizeof *gmtptr);
g_gmt_isset = gmtptr != NULL;
if (g_gmt_isset)
{
gmtload(gmtptr);
}
}
return timesub(timep, offset, gmtptr, tmp);
}
/* 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(const int y)
{
return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
-(leaps_thru_end_of(-(y + 1)) + 1);
}
static struct tm *timesub(FAR const time_t * const timep,
const int_fast32_t offset,
FAR const struct state_s *const sp,
struct tm *const tmp)
{
const struct lsinfo_s *lp;
time_t tdays;
int idays; /* unsigned would be so 2003 */
int_fast64_t rem;
int y;
FAR const int *ip;
int_fast64_t corr;
int hit;
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 >= g_year_lengths[isleap(y)])
{
int newy;
time_t tdelta;
int idelta;
int leapdays;
tdelta = tdays / DAYSPERLYEAR;
if (!((!TYPE_SIGNED(time_t) || INT_MIN <= tdelta) && tdelta <= INT_MAX))
{
return NULL;
}
idelta = 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;
}
{
int_fast32_t seconds;
seconds = tdays * SECSPERDAY;
tdays = seconds / SECSPERDAY;
rem += seconds - tdays * SECSPERDAY;
}
/* Given the range, we can now fearlessly cast */
idays = 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 += g_year_lengths[isleap(y)];
}
while (idays >= g_year_lengths[isleap(y)])
{
idays -= g_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 = g_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;
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).
*/
/* Normalize logic courtesy Paul Eggert */
static int increment_overflow(FAR int *const ip, int j)
{
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(FAR int_fast32_t * const lp, int const m)
{
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 increment_overflow_time(time_t * tp, int_fast32_t j)
{
/* This is like
* 'if (! (g_min_timet <= *tp + j && *tp + j <= g_max_timet)) ...',
* except that it does the right thing even if *tp + j would overflow.
*/
if (!(j < 0
? (TYPE_SIGNED(time_t) ? g_min_timet - j <= *tp : -1 - j < *tp)
: *tp <= g_max_timet - j))
{
return TRUE;
}
*tp += j;
return FALSE;
}
static int normalize_overflow(FAR int *const tensptr,
FAR int *const unitsptr, const int base)
{
int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) : (-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow(tensptr, tensdelta);
}
static int normalize_overflow32(FAR int_fast32_t * const tensptr,
FAR int *const unitsptr, const int base)
{
int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) : (-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow32(tensptr, tensdelta);
}
static int tmcomp(FAR const struct tm *atmp, FAR const struct tm *btmp)
{
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,
FAR struct tm *(*const funcp)(FAR const time_t *,
int_fast32_t, struct tm *),
const int_fast32_t offset, FAR int *const okayp,
const int do_norm_secs)
{
FAR const struct state_s *sp;
int dir;
int i, j;
int saved_seconds;
int_fast32_t li;
time_t lo;
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 -1;
}
}
if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
{
return -1;
}
if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
{
return -1;
}
y = yourtm.tm_year;
if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR))
{
return -1;
}
/* 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 -1;
}
while (yourtm.tm_mday <= 0)
{
if (increment_overflow32(&y, -1))
{
return -1;
}
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday += g_year_lengths[isleap(li)];
}
while (yourtm.tm_mday > DAYSPERLYEAR)
{
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday -= g_year_lengths[isleap(li)];
if (increment_overflow32(&y, 1))
{
return -1;
}
}
for (;;)
{
i = g_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 -1;
}
}
}
if (increment_overflow32(&y, -TM_YEAR_BASE))
{
return -1;
}
yourtm.tm_year = y;
if (yourtm.tm_year != y)
{
return -1;
}
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 -1;
}
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 == g_max_timet)
{
return -1;
}
++t;
++lo;
}
else if (t == hi)
{
if (t == g_min_timet)
{
return -1;
}
--t;
--hi;
}
if (lo > hi)
{
return -1;
}
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 = (FAR const struct state_s *)((funcp == localsub) ? lclptr : gmtptr);
if (sp == NULL)
{
return -1;
}
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 -1;
}
label:
newt = t + saved_seconds;
if ((newt < t) != (saved_seconds < 0))
{
return -1;
}
t = newt;
if ((*funcp) (&t, offset, tmp))
{
*okayp = TRUE;
}
return t;
}
static time_t time2(FAR struct tm *const tmp,
FAR struct tm *(*const funcp)(FAR const time_t *,
int_fast32_t, struct tm *),
const int_fast32_t offset, FAR 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(FAR struct tm *const tmp,
FAR struct tm *(*const funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
const int_fast32_t offset)
{
time_t t;
FAR const struct state_s *sp;
int samei, otheri;
int sameind, otherind;
int i;
int nseen;
char seen[TZ_MAX_TYPES];
unsigned char types[TZ_MAX_TYPES];
int okay;
if (tmp == NULL)
{
errno = EINVAL;
return -1;
}
if (tmp->tm_isdst > 1)
{
tmp->tm_isdst = 1;
}
t = time2(tmp, funcp, offset, &okay);
if (okay)
{
return t;
}
if (tmp->tm_isdst < 0)
{
return t;
}
/* 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 = (FAR const struct state_s *)((funcp == localsub) ? lclptr : gmtptr);
if (sp == NULL)
{
return -1;
}
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 -1;
}
/****************************************************************************
* Public Functions
****************************************************************************/
void tzset(void)
{
FAR const char *name;
name = getenv("TZ");
if (name == NULL)
{
tzsetwall();
return;
}
if (g_lcl_isset > 0 && strcmp(g_lcl_tzname, name) == 0)
{
return;
}
g_lcl_isset = strlen(name) < sizeof g_lcl_tzname;
if (g_lcl_isset)
{
(void)strcpy(g_lcl_tzname, name);
}
if (lclptr == NULL)
{
lclptr = malloc(sizeof *lclptr);
if (lclptr == NULL)
{
settzname(); /* all we can do */
return;
}
}
if (*name == '\0')
{
/* User wants it fast rather than right */
lclptr->leapcnt = 0; /* so, we're off a little */
lclptr->timecnt = 0;
lclptr->typecnt = 0;
lclptr->ttis[0].tt_isdst = 0;
lclptr->ttis[0].tt_gmtoff = 0;
lclptr->ttis[0].tt_abbrind = 0;
(void)strcpy(lclptr->chars, GMT);
}
else if (tzload(name, lclptr, TRUE) != 0)
{
if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
{
(void)gmtload(lclptr);
}
}
settzname();
}
FAR struct tm *localtime(FAR const time_t * const timep)
{
tzset();
return localsub(timep, 0L, &g_tm);
}
/* Re-entrant version of localtime */
FAR struct tm *localtime_r(FAR const time_t * const timep, struct tm *tmp)
{
return localsub(timep, 0L, tmp);
}
FAR struct tm *gmtime(FAR const time_t * const timep)
{
return gmtsub(timep, 0L, &g_tm);
}
/* Re-entrant version of gmtime */
FAR struct tm *gmtime_r(FAR const time_t * const timep, struct tm *tmp)
{
return gmtsub(timep, 0L, tmp);
}
#if 0 /* No asctime() */
FAR char *ctime(FAR const time_t * const timep)
{
/* Section 4.12.3.2 of X3.159-1989 requires that
* The ctime function converts the calendar time pointed to by timer
* to local time in the form of a string. It is equivalent to
* asctime(localtime(timer))
*/
return asctime(localtime(timep));
}
#endif
#if 0 /* No asctime_r */
FAR char *ctime_r(FAR const time_t * const timep, char *buf)
{
struct tm mytm;
return asctime_r(localtime_r(timep, &mytm), buf);
}
#endif
time_t mktime(struct tm * const tmp)
{
tzset();
return time1(tmp, localsub, 0L);
}
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