diff options
Diffstat (limited to 'intl/icu/source/tools/tzcode/localtime.c')
| -rw-r--r-- | intl/icu/source/tools/tzcode/localtime.c | 2056 |
1 files changed, 2056 insertions, 0 deletions
diff --git a/intl/icu/source/tools/tzcode/localtime.c b/intl/icu/source/tools/tzcode/localtime.c new file mode 100644 index 000000000..ff07c7092 --- /dev/null +++ b/intl/icu/source/tools/tzcode/localtime.c @@ -0,0 +1,2056 @@ +/* +** 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. +*/ + +/*LINTLIBRARY*/ + +#include "private.h" +#include "tzfile.h" +#include "fcntl.h" + +#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 */ + +/* +** SunOS 4.1.1 headers lack O_BINARY. +*/ + +#ifdef O_BINARY +#define OPEN_MODE (O_RDONLY | O_BINARY) +#endif /* defined O_BINARY */ +#ifndef O_BINARY +#define OPEN_MODE O_RDONLY +#endif /* !defined O_BINARY */ + +#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 */ + +static const char wildabbr[] = WILDABBR; + +static const char gmt[] = "GMT"; + +/* +** 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. +*/ +#ifndef TZDEFRULESTRING +#define TZDEFRULESTRING ",M4.1.0,M10.5.0" +#endif /* !defined TZDEFDST */ + +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 int_fast32_t detzcode(const char * codep); +static int_fast64_t detzcode64(const char * codep); +static int differ_by_repeat(time_t t1, time_t t0); +static const char * getzname(const char * strp) ATTRIBUTE_PURE; +static const char * getqzname(const char * strp, const int delim) + ATTRIBUTE_PURE; +static const char * getnum(const char * strp, int * nump, int min, + int max); +static const char * getsecs(const char * strp, int_fast32_t * secsp); +static const char * getoffset(const char * strp, int_fast32_t * offsetp); +static const char * getrule(const char * strp, struct rule * rulep); +static void gmtload(struct state * sp); +static struct tm * gmtsub(const time_t * timep, int_fast32_t offset, + struct tm * tmp); +static struct tm * localsub(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 increment_overflow_time(time_t *t, int_fast32_t delta); +static int normalize_overflow32(int_fast32_t * tensptr, + int * unitsptr, int base); +static int normalize_overflow(int * tensptr, int * unitsptr, + int base); +static void settzname(void); +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 int_fast32_t transtime(int year, const struct rule * rulep, + int_fast32_t offset) + ATTRIBUTE_PURE; +static int typesequiv(const struct state * sp, int a, int b); +static int tzload(const char * name, struct state * sp, + int doextend); +static int tzparse(const char * name, struct state * sp, + int lastditch); + +#ifdef ALL_STATE +static struct state * lclptr; +static struct state * gmtptr; +#endif /* defined ALL_STATE */ + +#ifndef ALL_STATE +static struct state lclmem; +static struct state gmtmem; +#define lclptr (&lclmem) +#define gmtptr (&gmtmem) +#endif /* State Farm */ + +#ifndef TZ_STRLEN_MAX +#define TZ_STRLEN_MAX 255 +#endif /* !defined TZ_STRLEN_MAX */ + +static char lcl_TZname[TZ_STRLEN_MAX + 1]; +static int lcl_is_set; +static int gmt_is_set; + +char * tzname[2] = { + (char *) wildabbr, + (char *) wildabbr +}; + +/* +** 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 tm; + +#ifdef USG_COMPAT +long timezone = 0; +int daylight = 0; +#endif /* defined USG_COMPAT */ + +#ifdef ALTZONE +long altzone = 0; +#endif /* defined ALTZONE */ + +static int_fast32_t +detzcode(const char *const codep) +{ + register int_fast32_t result; + register 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(const char *const codep) +{ + register int_fast64_t result; + register 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) +{ + register struct state * const sp = lclptr; + register int i; + + tzname[0] = tzname[1] = (char *) wildabbr; +#ifdef USG_COMPAT + daylight = 0; + timezone = 0; +#endif /* defined USG_COMPAT */ +#ifdef ALTZONE + altzone = 0; +#endif /* defined ALTZONE */ + if (sp == NULL) { + tzname[0] = tzname[1] = (char *) gmt; + return; + } + /* + ** And to get the latest zone names into tzname. . . + */ + for (i = 0; i < sp->typecnt; ++i) { + register const struct ttinfo * const ttisp = &sp->ttis[i]; + + tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; + } + for (i = 0; i < sp->timecnt; ++i) { + register const struct ttinfo * const ttisp = + &sp->ttis[ + sp->types[i]]; + + tzname[ttisp->tt_isdst] = + &sp->chars[ttisp->tt_abbrind]; +#ifdef USG_COMPAT + if (ttisp->tt_isdst) + daylight = 1; + if (!ttisp->tt_isdst) + timezone = -(ttisp->tt_gmtoff); +#endif /* defined USG_COMPAT */ +#ifdef ALTZONE + if (ttisp->tt_isdst) + altzone = -(ttisp->tt_gmtoff); +#endif /* defined ALTZONE */ + } + /* + ** 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) { + register const struct ttinfo * const ttisp = &sp->ttis[i]; + register 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(register const char *name, register struct state *const sp, + register const int doextend) +{ + register const char * p; + register int i; + register int fid; + register int stored; + register int nread; + typedef union { + struct tzhead tzhead; + char buf[2 * sizeof(struct tzhead) + + 2 * sizeof *sp + + 4 * TZ_MAX_TIMES]; + } u_t; +#ifdef ALL_STATE + register u_t * const up = malloc(sizeof *up); +#else /* !defined ALL_STATE */ + u_t u; + register u_t * const up = &u; +#endif /* !defined ALL_STATE */ + + sp->goback = sp->goahead = FALSE; + + if (up == NULL) + return -1; + + if (name == NULL && (name = TZDEFAULT) == NULL) + goto oops; + { + register int doaccess; + /* + ** 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]; + + if (name[0] == ':') + ++name; + doaccess = name[0] == '/'; + if (!doaccess) { + if ((p = TZDIR) == NULL) + goto oops; + if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) + goto oops; + (void) strcpy(fullname, p); + (void) strcat(fullname, "/"); + (void) strcat(fullname, name); + /* + ** Set doaccess if '.' (as in "../") shows up in name. + */ + if (strchr(name, '.') != NULL) + doaccess = TRUE; + name = fullname; + } + if (doaccess && access(name, R_OK) != 0) + goto oops; + if ((fid = open(name, OPEN_MODE)) == -1) + 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.tzh_ttisstdcnt); + ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt); + sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt); + sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt); + sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt); + sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt); + p = up->tzhead.tzh_charcnt + sizeof up->tzhead.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) + ? time_t_min <= at + : 0 <= at) + && at <= time_t_max); + if (sp->types[i]) { + if (i && !timecnt && at != time_t_min) { + /* + ** 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++] = time_t_min; + } + 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) { + register struct ttinfo * 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) { + register struct lsinfo * 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) { + register struct ttinfo * 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) { + register struct ttinfo * 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.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) { + struct state ts; + register 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; +#ifdef ALL_STATE + free(up); +#endif /* defined ALL_STATE */ + return 0; +oops: +#ifdef ALL_STATE + free(up); +#endif /* defined ALL_STATE */ + return -1; +} + +static int +typesequiv(const struct state *const sp, const int a, const int b) +{ + register int result; + + if (sp == NULL || + a < 0 || a >= sp->typecnt || + b < 0 || b >= sp->typecnt) + result = FALSE; + else { + register const struct ttinfo * ap = &sp->ttis[a]; + register const struct ttinfo * 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; +} + +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 +}; + +/* +** 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 const char * +getzname(register const char *strp) +{ + register 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 const char * +getqzname(register const char *strp, const int delim) +{ + register 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 const char * +getnum(register const char *strp, int *const nump, const int min, const int max) +{ + register char c; + register 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 const char * +getsecs(register const char *strp, 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 const char * +getoffset(register const char *strp, int_fast32_t *const offsetp) +{ + register 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 const char * +getrule(const char *strp, register struct rule *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, register const struct rule *const rulep, + const int_fast32_t offset) +{ + register int leapyear; + register int_fast32_t value; + register int i; + int d, m1, yy0, yy1, yy2, dow; + + INITIALIZE(value); + 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 >= + 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 += 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(const char *name, register struct state *const sp, + const int lastditch) +{ + const char * stdname; + const char * dstname; + size_t stdlen; + size_t dstlen; + int_fast32_t stdoffset; + int_fast32_t dstoffset; + register char * cp; + register int load_result; + static struct ttinfo zttinfo; + + INITIALIZE(dstname); + 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 start; + struct rule end; + register int year; + register int yearlim; + register 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 = (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 { + register int_fast32_t theirstdoffset; + register int_fast32_t theirdstoffset; + register int_fast32_t theiroffset; + register int isdst; + register int i; + register 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(struct state *const sp) +{ + if (tzload(gmt, sp, TRUE) != 0) + (void) tzparse(gmt, sp, TRUE); +} + +#ifndef STD_INSPIRED +/* +** A non-static declaration of tzsetwall in a system header file +** may cause a warning about this upcoming static declaration... +*/ +static +#endif /* !defined STD_INSPIRED */ +void +tzsetwall(void) +{ + if (lcl_is_set < 0) + return; + lcl_is_set = -1; + +#ifdef ALL_STATE + if (lclptr == NULL) { + lclptr = malloc(sizeof *lclptr); + if (lclptr == NULL) { + settzname(); /* all we can do */ + return; + } + } +#endif /* defined ALL_STATE */ + if (tzload(NULL, lclptr, TRUE) != 0) + gmtload(lclptr); + settzname(); +} + +void +tzset(void) +{ + register const char * name; + + name = getenv("TZ"); + if (name == NULL) { + tzsetwall(); + return; + } + + if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) + return; + lcl_is_set = strlen(name) < sizeof lcl_TZname; + if (lcl_is_set) + (void) strcpy(lcl_TZname, name); + +#ifdef ALL_STATE + if (lclptr == NULL) { + lclptr = malloc(sizeof *lclptr); + if (lclptr == NULL) { + settzname(); /* all we can do */ + return; + } + } +#endif /* defined ALL_STATE */ + 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(); +} + +/* +** 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. +*/ + +/*ARGSUSED*/ +static struct tm * +localsub(const time_t *const timep, const int_fast32_t offset, + struct tm *const tmp) +{ + register struct state * sp; + register const struct ttinfo * ttisp; + register int i; + register 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; + register time_t seconds; + register 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) { + register 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 { + register int lo = 1; + register int hi = sp->timecnt; + + while (lo < hi) { + register 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]; +#ifdef TM_ZONE + tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; +#endif /* defined TM_ZONE */ + return result; +} + +struct tm * +localtime(const time_t *const timep) +{ + tzset(); + return localsub(timep, 0L, &tm); +} + +/* +** Re-entrant version of localtime. +*/ + +struct tm * +localtime_r(const time_t *const timep, struct tm *tmp) +{ + return localsub(timep, 0L, tmp); +} + +/* +** 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; +#ifdef ALL_STATE + gmtptr = malloc(sizeof *gmtptr); +#endif /* defined ALL_STATE */ + 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; +} + +struct tm * +gmtime(const time_t *const timep) +{ + return gmtsub(timep, 0L, &tm); +} + +/* +* Re-entrant version of gmtime. +*/ + +struct tm * +gmtime_r(const time_t *const timep, struct tm *tmp) +{ + return gmtsub(timep, 0L, tmp); +} + +#ifdef STD_INSPIRED + +struct tm * +offtime(const time_t *const timep, const long offset) +{ + return gmtsub(timep, offset, &tm); +} + +#endif /* defined STD_INSPIRED */ + +/* +** 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 = 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 = 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 += 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; +} + +char * +ctime(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)); +} + +char * +ctime_r(const time_t *const timep, char *buf) +{ + struct tm mytm; + + return asctime_r(localtime_r(timep, &mytm), buf); +} + +/* +** 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 +increment_overflow_time(time_t *tp, int_fast32_t j) +{ + /* + ** This is like + ** 'if (! (time_t_min <= *tp + j && *tp + j <= time_t_max)) ...', + ** except that it does the right thing even if *tp + j would overflow. + */ + if (! (j < 0 + ? (TYPE_SIGNED(time_t) ? time_t_min - j <= *tp : -1 - j < *tp) + : *tp <= time_t_max - j)) + return TRUE; + *tp += j; + 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 *) + ((funcp == localsub) ? lclptr : 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 *) ((funcp == localsub) ? lclptr : 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 +mktime(struct tm *const tmp) +{ + tzset(); + return time1(tmp, localsub, 0L); +} + +#ifdef STD_INSPIRED + +time_t +timelocal(struct tm *const tmp) +{ + if (tmp != NULL) + tmp->tm_isdst = -1; /* in case it wasn't initialized */ + return mktime(tmp); +} + +time_t +timegm(struct tm *const tmp) +{ + if (tmp != NULL) + tmp->tm_isdst = 0; + return time1(tmp, gmtsub, 0L); +} + +time_t +timeoff(struct tm *const tmp, const long offset) +{ + if (tmp != NULL) + tmp->tm_isdst = 0; + return time1(tmp, gmtsub, offset); +} + +#endif /* defined STD_INSPIRED */ + +#ifdef CMUCS + +/* +** The following is supplied for compatibility with +** previous versions of the CMUCS runtime library. +*/ + +long +gtime(struct tm *const tmp) +{ + const time_t t = mktime(tmp); + + if (t == WRONG) + return -1; + return t; +} + +#endif /* defined CMUCS */ + +/* +** XXX--is the below the right way to conditionalize?? +*/ + +#ifdef STD_INSPIRED + +/* +** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 +** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which +** is not the case if we are accounting for leap seconds. +** So, we provide the following conversion routines for use +** when exchanging timestamps with POSIX conforming systems. +*/ + +static int_fast64_t +leapcorr(time_t *timep) +{ + register struct state * sp; + register struct lsinfo * lp; + register int i; + + sp = lclptr; + i = sp->leapcnt; + while (--i >= 0) { + lp = &sp->lsis[i]; + if (*timep >= lp->ls_trans) + return lp->ls_corr; + } + return 0; +} + +time_t +time2posix(time_t t) +{ + tzset(); + return t - leapcorr(&t); +} + +time_t +posix2time(time_t t) +{ + time_t x; + time_t y; + + tzset(); + /* + ** For a positive leap second hit, the result + ** is not unique. For a negative leap second + ** hit, the corresponding time doesn't exist, + ** so we return an adjacent second. + */ + x = t + leapcorr(&t); + y = x - leapcorr(&x); + if (y < t) { + do { + x++; + y = x - leapcorr(&x); + } while (y < t); + if (t != y) + return x - 1; + } else if (y > t) { + do { + --x; + y = x - leapcorr(&x); + } while (y > t); + if (t != y) + return x + 1; + } + return x; +} + +#endif /* defined STD_INSPIRED */ |