1/*
2** This file is in the public domain, so clarified as of
3** 1996-06-05 by Arthur David Olson.
4*/
5
6#ifndef lint
7#ifndef NOID
8static char elsieid[] = "@(#)localtime.c    8.3";
9#endif /* !defined NOID */
10#endif /* !defined lint */
11
12/*
13** Leap second handling from Bradley White.
14** POSIX-style TZ environment variable handling from Guy Harris.
15*/
16
17/*LINTLIBRARY*/
18
19#include "private.h"
20#include "tzfile.h"
21#include "fcntl.h"
22#include "float.h"  /* for FLT_MAX and DBL_MAX */
23
24#include "thread_private.h"
25#include <sys/system_properties.h>
26
27#ifndef TZ_ABBR_MAX_LEN
28#define TZ_ABBR_MAX_LEN 16
29#endif /* !defined TZ_ABBR_MAX_LEN */
30
31#ifndef TZ_ABBR_CHAR_SET
32#define TZ_ABBR_CHAR_SET \
33    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
34#endif /* !defined TZ_ABBR_CHAR_SET */
35
36#ifndef TZ_ABBR_ERR_CHAR
37#define TZ_ABBR_ERR_CHAR    '_'
38#endif /* !defined TZ_ABBR_ERR_CHAR */
39
40#define INDEXFILE "/system/usr/share/zoneinfo/zoneinfo.idx"
41#define DATAFILE "/system/usr/share/zoneinfo/zoneinfo.dat"
42#define NAMELEN 40
43#define INTLEN 4
44#define READLEN (NAMELEN + 3 * INTLEN)
45
46/*
47** SunOS 4.1.1 headers lack O_BINARY.
48*/
49
50#ifdef O_BINARY
51#define OPEN_MODE   (O_RDONLY | O_BINARY)
52#endif /* defined O_BINARY */
53#ifndef O_BINARY
54#define OPEN_MODE   O_RDONLY
55#endif /* !defined O_BINARY */
56
57#if 0
58#  define  XLOG(xx)  printf xx , fflush(stdout)
59#else
60#  define  XLOG(x)   do{}while (0)
61#endif
62
63/* Add the following function implementations:
64 *  timelocal()
65 *  timegm()
66 *  time2posix()
67 *  posix2time()
68 */
69#define STD_INSPIRED 1
70
71/* THREAD-SAFETY SUPPORT GOES HERE */
72static pthread_mutex_t  _tzMutex = PTHREAD_MUTEX_INITIALIZER;
73
74static __inline__ void _tzLock(void)
75{
76    if (__isthreaded)
77        pthread_mutex_lock(&_tzMutex);
78}
79
80static __inline__ void _tzUnlock(void)
81{
82    if (__isthreaded)
83        pthread_mutex_unlock(&_tzMutex);
84}
85
86/* Complex computations to determine the min/max of time_t depending
87 * on TYPE_BIT / TYPE_SIGNED / TYPE_INTEGRAL.
88 * These macros cannot be used in pre-processor directives, so we
89 * let the C compiler do the work, which makes things a bit funky.
90 */
91static const time_t TIME_T_MAX =
92    TYPE_INTEGRAL(time_t) ?
93        ( TYPE_SIGNED(time_t) ?
94            ~((time_t)1 << (TYPE_BIT(time_t)-1))
95        :
96            ~(time_t)0
97        )
98    : /* if time_t is a floating point number */
99        ( sizeof(time_t) > sizeof(float) ? (time_t)DBL_MAX : (time_t)FLT_MAX );
100
101static const time_t TIME_T_MIN =
102    TYPE_INTEGRAL(time_t) ?
103        ( TYPE_SIGNED(time_t) ?
104            ((time_t)1 << (TYPE_BIT(time_t)-1))
105        :
106            0
107        )
108    :
109        ( sizeof(time_t) > sizeof(float) ? (time_t)DBL_MIN : (time_t)FLT_MIN );
110
111#ifndef WILDABBR
112/*
113** Someone might make incorrect use of a time zone abbreviation:
114**  1.  They might reference tzname[0] before calling tzset (explicitly
115**      or implicitly).
116**  2.  They might reference tzname[1] before calling tzset (explicitly
117**      or implicitly).
118**  3.  They might reference tzname[1] after setting to a time zone
119**      in which Daylight Saving Time is never observed.
120**  4.  They might reference tzname[0] after setting to a time zone
121**      in which Standard Time is never observed.
122**  5.  They might reference tm.TM_ZONE after calling offtime.
123** What's best to do in the above cases is open to debate;
124** for now, we just set things up so that in any of the five cases
125** WILDABBR is used. Another possibility: initialize tzname[0] to the
126** string "tzname[0] used before set", and similarly for the other cases.
127** And another: initialize tzname[0] to "ERA", with an explanation in the
128** manual page of what this "time zone abbreviation" means (doing this so
129** that tzname[0] has the "normal" length of three characters).
130*/
131#define WILDABBR    "   "
132#endif /* !defined WILDABBR */
133
134static char     wildabbr[] = WILDABBR;
135
136static const char   gmt[] = "GMT";
137
138/*
139** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
140** We default to US rules as of 1999-08-17.
141** POSIX 1003.1 section 8.1.1 says that the default DST rules are
142** implementation dependent; for historical reasons, US rules are a
143** common default.
144*/
145#ifndef TZDEFRULESTRING
146#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
147#endif /* !defined TZDEFDST */
148
149struct ttinfo {             /* time type information */
150    long    tt_gmtoff;  /* UTC offset in seconds */
151    int     tt_isdst;   /* used to set tm_isdst */
152    int     tt_abbrind; /* abbreviation list index */
153    int     tt_ttisstd; /* TRUE if transition is std time */
154    int     tt_ttisgmt; /* TRUE if transition is UTC */
155};
156
157struct lsinfo {             /* leap second information */
158    time_t      ls_trans;   /* transition time */
159    long        ls_corr;    /* correction to apply */
160};
161
162#define BIGGEST(a, b)   (((a) > (b)) ? (a) : (b))
163
164#ifdef TZNAME_MAX
165#define MY_TZNAME_MAX   TZNAME_MAX
166#endif /* defined TZNAME_MAX */
167#ifndef TZNAME_MAX
168#define MY_TZNAME_MAX   255
169#endif /* !defined TZNAME_MAX */
170
171/* XXX: This code should really use time64_t instead of time_t
172 *      but we can't change it without re-generating the index
173 *      file first with the correct data.
174 */
175struct state {
176    int     leapcnt;
177    int     timecnt;
178    int     typecnt;
179    int     charcnt;
180    int     goback;
181    int     goahead;
182    time_t      ats[TZ_MAX_TIMES];
183    unsigned char   types[TZ_MAX_TIMES];
184    struct ttinfo   ttis[TZ_MAX_TYPES];
185    char        chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
186                (2 * (MY_TZNAME_MAX + 1)))];
187    struct lsinfo   lsis[TZ_MAX_LEAPS];
188};
189
190struct rule {
191    int     r_type;     /* type of rule--see below */
192    int     r_day;      /* day number of rule */
193    int     r_week;     /* week number of rule */
194    int     r_mon;      /* month number of rule */
195    long        r_time;     /* transition time of rule */
196};
197
198#define JULIAN_DAY      0   /* Jn - Julian day */
199#define DAY_OF_YEAR     1   /* n - day of year */
200#define MONTH_NTH_DAY_OF_WEEK   2   /* Mm.n.d - month, week, day of week */
201
202/*
203** Prototypes for static functions.
204*/
205
206/* NOTE: all internal functions assume that _tzLock() was already called */
207
208static long     detzcode P((const char * codep));
209static time_t   detzcode64 P((const char * codep));
210static int      differ_by_repeat P((time_t t1, time_t t0));
211static const char * getzname P((const char * strp));
212static const char * getqzname P((const char * strp, const int delim));
213static const char * getnum P((const char * strp, int * nump, int min,
214                int max));
215static const char * getsecs P((const char * strp, long * secsp));
216static const char * getoffset P((const char * strp, long * offsetp));
217static const char * getrule P((const char * strp, struct rule * rulep));
218static void     gmtload P((struct state * sp));
219static struct tm *  gmtsub P((const time_t * timep, long offset,
220                struct tm * tmp));
221static struct tm *  localsub P((const time_t * timep, long offset,
222                struct tm * tmp));
223static int      increment_overflow P((int * number, int delta));
224static int      leaps_thru_end_of P((int y));
225static int      long_increment_overflow P((long * number, int delta));
226static int      long_normalize_overflow P((long * tensptr,
227                int * unitsptr, int base));
228static int      normalize_overflow P((int * tensptr, int * unitsptr,
229                int base));
230static void     settzname P((void));
231static time_t       time1 P((struct tm * tmp,
232                struct tm * (*funcp) P((const time_t *,
233                long, struct tm *)),
234                long offset));
235static time_t       time2 P((struct tm *tmp,
236                struct tm * (*funcp) P((const time_t *,
237                long, struct tm*)),
238                long offset, int * okayp));
239static time_t       time2sub P((struct tm *tmp,
240                struct tm * (*funcp) P((const time_t *,
241                long, struct tm*)),
242                long offset, int * okayp, int do_norm_secs));
243static struct tm *  timesub P((const time_t * timep, long offset,
244                const struct state * sp, struct tm * tmp));
245static int      tmcomp P((const struct tm * atmp,
246                const struct tm * btmp));
247static time_t       transtime P((time_t janfirst, int year,
248                const struct rule * rulep, long offset));
249static int      tzload P((const char * name, struct state * sp,
250                int doextend));
251static int      tzparse P((const char * name, struct state * sp,
252                int lastditch));
253
254#ifdef ALL_STATE
255static struct state *   lclptr;
256static struct state *   gmtptr;
257#endif /* defined ALL_STATE */
258
259#ifndef ALL_STATE
260static struct state lclmem;
261static struct state gmtmem;
262#define lclptr      (&lclmem)
263#define gmtptr      (&gmtmem)
264#endif /* State Farm */
265
266#ifndef TZ_STRLEN_MAX
267#define TZ_STRLEN_MAX 255
268#endif /* !defined TZ_STRLEN_MAX */
269
270static char     lcl_TZname[TZ_STRLEN_MAX + 1];
271static int      lcl_is_set;
272static int      gmt_is_set;
273
274char *          tzname[2] = {
275    wildabbr,
276    wildabbr
277};
278
279/*
280** Section 4.12.3 of X3.159-1989 requires that
281**  Except for the strftime function, these functions [asctime,
282**  ctime, gmtime, localtime] return values in one of two static
283**  objects: a broken-down time structure and an array of char.
284** Thanks to Paul Eggert for noting this.
285*/
286
287static struct tm    tmGlobal;
288
289#ifdef USG_COMPAT
290time_t          timezone = 0;
291int         daylight = 0;
292#endif /* defined USG_COMPAT */
293
294#ifdef ALTZONE
295time_t          altzone = 0;
296#endif /* defined ALTZONE */
297
298static long
299detzcode(codep)
300const char * const  codep;
301{
302    register long   result;
303    register int    i;
304
305    result = (codep[0] & 0x80) ? ~0L : 0;
306    for (i = 0; i < 4; ++i)
307        result = (result << 8) | (codep[i] & 0xff);
308    return result;
309}
310
311static time_t
312detzcode64(codep)
313const char * const  codep;
314{
315    register time_t result;
316    register int    i;
317
318    result = (codep[0] & 0x80) ?  (~(int_fast64_t) 0) : 0;
319    for (i = 0; i < 8; ++i)
320        result = result * 256 + (codep[i] & 0xff);
321    return result;
322}
323
324static void
325settzname P((void))
326{
327    register struct state * const   sp = lclptr;
328    register int            i;
329
330    tzname[0] = wildabbr;
331    tzname[1] = wildabbr;
332#ifdef USG_COMPAT
333    daylight = 0;
334    timezone = 0;
335#endif /* defined USG_COMPAT */
336#ifdef ALTZONE
337    altzone = 0;
338#endif /* defined ALTZONE */
339#ifdef ALL_STATE
340    if (sp == NULL) {
341        tzname[0] = tzname[1] = gmt;
342        return;
343    }
344#endif /* defined ALL_STATE */
345    for (i = 0; i < sp->typecnt; ++i) {
346        register const struct ttinfo * const    ttisp = &sp->ttis[i];
347
348        tzname[ttisp->tt_isdst] =
349            &sp->chars[ttisp->tt_abbrind];
350#ifdef USG_COMPAT
351        if (ttisp->tt_isdst)
352            daylight = 1;
353        if (i == 0 || !ttisp->tt_isdst)
354            timezone = -(ttisp->tt_gmtoff);
355#endif /* defined USG_COMPAT */
356#ifdef ALTZONE
357        if (i == 0 || ttisp->tt_isdst)
358            altzone = -(ttisp->tt_gmtoff);
359#endif /* defined ALTZONE */
360    }
361    /*
362    ** And to get the latest zone names into tzname. . .
363    */
364    for (i = 0; i < sp->timecnt; ++i) {
365        register const struct ttinfo * const    ttisp =
366                            &sp->ttis[
367                                sp->types[i]];
368
369        tzname[ttisp->tt_isdst] =
370            &sp->chars[ttisp->tt_abbrind];
371    }
372    /*
373    ** Finally, scrub the abbreviations.
374    ** First, replace bogus characters.
375    */
376    for (i = 0; i < sp->charcnt; ++i)
377        if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
378            sp->chars[i] = TZ_ABBR_ERR_CHAR;
379    /*
380    ** Second, truncate long abbreviations.
381    */
382    for (i = 0; i < sp->typecnt; ++i) {
383        register const struct ttinfo * const    ttisp = &sp->ttis[i];
384        register char *             cp = &sp->chars[ttisp->tt_abbrind];
385
386        if (strlen(cp) > TZ_ABBR_MAX_LEN &&
387            strcmp(cp, GRANDPARENTED) != 0)
388                *(cp + TZ_ABBR_MAX_LEN) = '\0';
389    }
390}
391
392static int
393differ_by_repeat(t1, t0)
394const time_t    t1;
395const time_t    t0;
396{
397    if (TYPE_INTEGRAL(time_t) &&
398        TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
399            return 0;
400#if SECSPERREPEAT_BITS <= 32  /* to avoid compiler warning (condition is always false) */
401        return (t1 - t0) == SECSPERREPEAT;
402#else
403        return 0;
404#endif
405}
406
407static int toint(unsigned char *s) {
408    return (s[0] << 24) | (s[1] << 16) | (s[2] << 8) | s[3];
409}
410
411static int
412tzload(name, sp, doextend)
413register const char *       name;
414register struct state * const   sp;
415register const int      doextend;
416{
417    register const char *       p;
418    register int            i;
419    register int            fid;
420    register int            stored;
421    register int            nread;
422    union {
423        struct tzhead   tzhead;
424        char        buf[2 * sizeof(struct tzhead) +
425                    2 * sizeof *sp +
426                    4 * TZ_MAX_TIMES];
427    } u;
428    int                     toread = sizeof u.buf;
429
430        if (name == NULL && (name = TZDEFAULT) == NULL) {
431                XLOG(("tzload: null 'name' parameter\n" ));
432                return -1;
433        }
434    {
435        register int    doaccess;
436        /*
437        ** Section 4.9.1 of the C standard says that
438        ** "FILENAME_MAX expands to an integral constant expression
439        ** that is the size needed for an array of char large enough
440        ** to hold the longest file name string that the implementation
441        ** guarantees can be opened."
442        */
443        char        fullname[FILENAME_MAX + 1];
444        char        *origname = (char*) name;
445
446        if (name[0] == ':')
447            ++name;
448        doaccess = name[0] == '/';
449        if (!doaccess) {
450            if ((p = TZDIR) == NULL) {
451                XLOG(("tzload: null TZDIR macro ?\n" ));
452                return -1;
453            }
454            if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) {
455                XLOG(( "tzload: path too long: %s/%s\n", p, name ));
456                return -1;
457            }
458            (void) strcpy(fullname, p);
459            (void) strcat(fullname, "/");
460            (void) strcat(fullname, name);
461            /*
462            ** Set doaccess if '.' (as in "../") shows up in name.
463            */
464            if (strchr(name, '.') != NULL)
465                doaccess = TRUE;
466            name = fullname;
467        }
468        if (doaccess && access(name, R_OK) != 0) {
469            XLOG(( "tzload: could not find '%s'\n", name ));
470            return -1;
471        }
472        if ((fid = open(name, OPEN_MODE)) == -1) {
473            char buf[READLEN];
474            char name[NAMELEN + 1];
475            int fidix = open(INDEXFILE, OPEN_MODE);
476            int off = -1;
477
478            XLOG(( "tzload: could not open '%s', trying '%s'\n", fullname, INDEXFILE ));
479            if (fidix < 0) {
480                XLOG(( "tzload: could not find '%s'\n", INDEXFILE ));
481                return -1;
482            }
483
484            while (read(fidix, buf, sizeof(buf)) == sizeof(buf)) {
485                memcpy(name, buf, NAMELEN);
486                name[NAMELEN] = '\0';
487
488                if (strcmp(name, origname) == 0) {
489                    off = toint((unsigned char *) buf + NAMELEN);
490                    toread = toint((unsigned char *) buf + NAMELEN + INTLEN);
491                    break;
492                }
493            }
494
495            close(fidix);
496
497            if (off < 0) {
498                XLOG(( "tzload: invalid offset (%d)\n", off ));
499                return -1;
500            }
501
502            fid = open(DATAFILE, OPEN_MODE);
503
504            if (fid < 0) {
505                XLOG(( "tzload: could not open '%s'\n", DATAFILE ));
506                return -1;
507            }
508
509            if (lseek(fid, off, SEEK_SET) < 0) {
510                XLOG(( "tzload: could not seek to %d in '%s'\n", off, DATAFILE ));
511                return -1;
512            }
513        }
514    }
515    nread = read(fid, u.buf, toread);
516        if (close(fid) < 0 || nread <= 0) {
517            XLOG(( "tzload: could not read content of '%s'\n", DATAFILE ));
518            return -1;
519        }
520    for (stored = 4; stored <= 8; stored *= 2) {
521        int     ttisstdcnt;
522        int     ttisgmtcnt;
523
524        ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
525        ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
526        sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
527        sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
528        sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
529        sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
530        p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
531        if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
532            sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
533            sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
534            sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
535            (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
536            (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
537                return -1;
538        if (nread - (p - u.buf) <
539            sp->timecnt * stored +      /* ats */
540            sp->timecnt +           /* types */
541            sp->typecnt * 6 +       /* ttinfos */
542            sp->charcnt +           /* chars */
543            sp->leapcnt * (stored + 4) +    /* lsinfos */
544            ttisstdcnt +            /* ttisstds */
545            ttisgmtcnt)         /* ttisgmts */
546                return -1;
547        for (i = 0; i < sp->timecnt; ++i) {
548            sp->ats[i] = (stored == 4) ?
549                detzcode(p) : detzcode64(p);
550            p += stored;
551        }
552        for (i = 0; i < sp->timecnt; ++i) {
553            sp->types[i] = (unsigned char) *p++;
554            if (sp->types[i] >= sp->typecnt)
555                return -1;
556        }
557        for (i = 0; i < sp->typecnt; ++i) {
558            register struct ttinfo *    ttisp;
559
560            ttisp = &sp->ttis[i];
561            ttisp->tt_gmtoff = detzcode(p);
562            p += 4;
563            ttisp->tt_isdst = (unsigned char) *p++;
564            if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
565                return -1;
566            ttisp->tt_abbrind = (unsigned char) *p++;
567            if (ttisp->tt_abbrind < 0 ||
568                ttisp->tt_abbrind > sp->charcnt)
569                    return -1;
570        }
571        for (i = 0; i < sp->charcnt; ++i)
572            sp->chars[i] = *p++;
573        sp->chars[i] = '\0';    /* ensure '\0' at end */
574        for (i = 0; i < sp->leapcnt; ++i) {
575            register struct lsinfo *    lsisp;
576
577            lsisp = &sp->lsis[i];
578            lsisp->ls_trans = (stored == 4) ?
579                detzcode(p) : detzcode64(p);
580            p += stored;
581            lsisp->ls_corr = detzcode(p);
582            p += 4;
583        }
584        for (i = 0; i < sp->typecnt; ++i) {
585            register struct ttinfo *    ttisp;
586
587            ttisp = &sp->ttis[i];
588            if (ttisstdcnt == 0)
589                ttisp->tt_ttisstd = FALSE;
590            else {
591                ttisp->tt_ttisstd = *p++;
592                if (ttisp->tt_ttisstd != TRUE &&
593                    ttisp->tt_ttisstd != FALSE)
594                        return -1;
595            }
596        }
597        for (i = 0; i < sp->typecnt; ++i) {
598            register struct ttinfo *    ttisp;
599
600            ttisp = &sp->ttis[i];
601            if (ttisgmtcnt == 0)
602                ttisp->tt_ttisgmt = FALSE;
603            else {
604                ttisp->tt_ttisgmt = *p++;
605                if (ttisp->tt_ttisgmt != TRUE &&
606                    ttisp->tt_ttisgmt != FALSE)
607                        return -1;
608            }
609        }
610        /*
611        ** Out-of-sort ats should mean we're running on a
612        ** signed time_t system but using a data file with
613        ** unsigned values (or vice versa).
614        */
615        for (i = 0; i < sp->timecnt - 2; ++i)
616            if (sp->ats[i] > sp->ats[i + 1]) {
617                ++i;
618                if (TYPE_SIGNED(time_t)) {
619                    /*
620                    ** Ignore the end (easy).
621                    */
622                    sp->timecnt = i;
623                } else {
624                    /*
625                    ** Ignore the beginning (harder).
626                    */
627                    register int    j;
628
629                    for (j = 0; j + i < sp->timecnt; ++j) {
630                        sp->ats[j] = sp->ats[j + i];
631                        sp->types[j] = sp->types[j + i];
632                    }
633                    sp->timecnt = j;
634                }
635                break;
636            }
637        /*
638        ** If this is an old file, we're done.
639        */
640        if (u.tzhead.tzh_version[0] == '\0')
641            break;
642        nread -= p - u.buf;
643        for (i = 0; i < nread; ++i)
644            u.buf[i] = p[i];
645        /*
646        ** If this is a narrow integer time_t system, we're done.
647        */
648        if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
649            break;
650    }
651    if (doextend && nread > 2 &&
652        u.buf[0] == '\n' && u.buf[nread - 1] == '\n' &&
653        sp->typecnt + 2 <= TZ_MAX_TYPES) {
654            struct state    ts;
655            register int    result;
656
657            u.buf[nread - 1] = '\0';
658            result = tzparse(&u.buf[1], &ts, FALSE);
659            if (result == 0 && ts.typecnt == 2 &&
660                sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) {
661                    for (i = 0; i < 2; ++i)
662                        ts.ttis[i].tt_abbrind +=
663                            sp->charcnt;
664                    for (i = 0; i < ts.charcnt; ++i)
665                        sp->chars[sp->charcnt++] =
666                            ts.chars[i];
667                    i = 0;
668                    while (i < ts.timecnt &&
669                        ts.ats[i] <=
670                        sp->ats[sp->timecnt - 1])
671                            ++i;
672                    while (i < ts.timecnt &&
673                        sp->timecnt < TZ_MAX_TIMES) {
674                        sp->ats[sp->timecnt] =
675                            ts.ats[i];
676                        sp->types[sp->timecnt] =
677                            sp->typecnt +
678                            ts.types[i];
679                        ++sp->timecnt;
680                        ++i;
681                    }
682                    sp->ttis[sp->typecnt++] = ts.ttis[0];
683                    sp->ttis[sp->typecnt++] = ts.ttis[1];
684            }
685    }
686    i = 2 * YEARSPERREPEAT;
687    sp->goback = sp->goahead = sp->timecnt > i;
688    sp->goback &= sp->types[i] == sp->types[0] &&
689        differ_by_repeat(sp->ats[i], sp->ats[0]);
690    sp->goahead &=
691        sp->types[sp->timecnt - 1] == sp->types[sp->timecnt - 1 - i] &&
692        differ_by_repeat(sp->ats[sp->timecnt - 1],
693             sp->ats[sp->timecnt - 1 - i]);
694        XLOG(( "tzload: load ok !!\n" ));
695    return 0;
696}
697
698static const int    mon_lengths[2][MONSPERYEAR] = {
699    { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
700    { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
701};
702
703static const int    year_lengths[2] = {
704    DAYSPERNYEAR, DAYSPERLYEAR
705};
706
707/*
708** Given a pointer into a time zone string, scan until a character that is not
709** a valid character in a zone name is found. Return a pointer to that
710** character.
711*/
712
713static const char *
714getzname(strp)
715register const char *   strp;
716{
717    register char   c;
718
719    while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
720        c != '+')
721            ++strp;
722    return strp;
723}
724
725/*
726** Given a pointer into an extended time zone string, scan until the ending
727** delimiter of the zone name is located. Return a pointer to the delimiter.
728**
729** As with getzname above, the legal character set is actually quite
730** restricted, with other characters producing undefined results.
731** We don't do any checking here; checking is done later in common-case code.
732*/
733
734static const char *
735getqzname(register const char *strp, const int delim)
736{
737    register int    c;
738
739    while ((c = *strp) != '\0' && c != delim)
740        ++strp;
741    return strp;
742}
743
744/*
745** Given a pointer into a time zone string, extract a number from that string.
746** Check that the number is within a specified range; if it is not, return
747** NULL.
748** Otherwise, return a pointer to the first character not part of the number.
749*/
750
751static const char *
752getnum(strp, nump, min, max)
753register const char *   strp;
754int * const     nump;
755const int       min;
756const int       max;
757{
758    register char   c;
759    register int    num;
760
761    if (strp == NULL || !is_digit(c = *strp))
762        return NULL;
763    num = 0;
764    do {
765        num = num * 10 + (c - '0');
766        if (num > max)
767            return NULL;    /* illegal value */
768        c = *++strp;
769    } while (is_digit(c));
770    if (num < min)
771        return NULL;        /* illegal value */
772    *nump = num;
773    return strp;
774}
775
776/*
777** Given a pointer into a time zone string, extract a number of seconds,
778** in hh[:mm[:ss]] form, from the string.
779** If any error occurs, return NULL.
780** Otherwise, return a pointer to the first character not part of the number
781** of seconds.
782*/
783
784static const char *
785getsecs(strp, secsp)
786register const char *   strp;
787long * const        secsp;
788{
789    int num;
790
791    /*
792    ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
793    ** "M10.4.6/26", which does not conform to Posix,
794    ** but which specifies the equivalent of
795    ** ``02:00 on the first Sunday on or after 23 Oct''.
796    */
797    strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
798    if (strp == NULL)
799        return NULL;
800    *secsp = num * (long) SECSPERHOUR;
801    if (*strp == ':') {
802        ++strp;
803        strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
804        if (strp == NULL)
805            return NULL;
806        *secsp += num * SECSPERMIN;
807        if (*strp == ':') {
808            ++strp;
809            /* `SECSPERMIN' allows for leap seconds. */
810            strp = getnum(strp, &num, 0, SECSPERMIN);
811            if (strp == NULL)
812                return NULL;
813            *secsp += num;
814        }
815    }
816    return strp;
817}
818
819/*
820** Given a pointer into a time zone string, extract an offset, in
821** [+-]hh[:mm[:ss]] form, from the string.
822** If any error occurs, return NULL.
823** Otherwise, return a pointer to the first character not part of the time.
824*/
825
826static const char *
827getoffset(strp, offsetp)
828register const char *   strp;
829long * const        offsetp;
830{
831    register int    neg = 0;
832
833    if (*strp == '-') {
834        neg = 1;
835        ++strp;
836    } else if (*strp == '+')
837        ++strp;
838    strp = getsecs(strp, offsetp);
839    if (strp == NULL)
840        return NULL;        /* illegal time */
841    if (neg)
842        *offsetp = -*offsetp;
843    return strp;
844}
845
846/*
847** Given a pointer into a time zone string, extract a rule in the form
848** date[/time]. See POSIX section 8 for the format of "date" and "time".
849** If a valid rule is not found, return NULL.
850** Otherwise, return a pointer to the first character not part of the rule.
851*/
852
853static const char *
854getrule(strp, rulep)
855const char *            strp;
856register struct rule * const    rulep;
857{
858    if (*strp == 'J') {
859        /*
860        ** Julian day.
861        */
862        rulep->r_type = JULIAN_DAY;
863        ++strp;
864        strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
865    } else if (*strp == 'M') {
866        /*
867        ** Month, week, day.
868        */
869        rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
870        ++strp;
871        strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
872        if (strp == NULL)
873            return NULL;
874        if (*strp++ != '.')
875            return NULL;
876        strp = getnum(strp, &rulep->r_week, 1, 5);
877        if (strp == NULL)
878            return NULL;
879        if (*strp++ != '.')
880            return NULL;
881        strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
882    } else if (is_digit(*strp)) {
883        /*
884        ** Day of year.
885        */
886        rulep->r_type = DAY_OF_YEAR;
887        strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
888    } else  return NULL;        /* invalid format */
889    if (strp == NULL)
890        return NULL;
891    if (*strp == '/') {
892        /*
893        ** Time specified.
894        */
895        ++strp;
896        strp = getsecs(strp, &rulep->r_time);
897    } else  rulep->r_time = 2 * SECSPERHOUR;    /* default = 2:00:00 */
898    return strp;
899}
900
901/*
902** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
903** year, a rule, and the offset from UTC at the time that rule takes effect,
904** calculate the Epoch-relative time that rule takes effect.
905*/
906
907static time_t
908transtime(janfirst, year, rulep, offset)
909const time_t                janfirst;
910const int               year;
911register const struct rule * const  rulep;
912const long              offset;
913{
914    register int    leapyear;
915    register time_t value;
916    register int    i;
917    int     d, m1, yy0, yy1, yy2, dow;
918
919    INITIALIZE(value);
920    leapyear = isleap(year);
921    switch (rulep->r_type) {
922
923    case JULIAN_DAY:
924        /*
925        ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
926        ** years.
927        ** In non-leap years, or if the day number is 59 or less, just
928        ** add SECSPERDAY times the day number-1 to the time of
929        ** January 1, midnight, to get the day.
930        */
931        value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
932        if (leapyear && rulep->r_day >= 60)
933            value += SECSPERDAY;
934        break;
935
936    case DAY_OF_YEAR:
937        /*
938        ** n - day of year.
939        ** Just add SECSPERDAY times the day number to the time of
940        ** January 1, midnight, to get the day.
941        */
942        value = janfirst + rulep->r_day * SECSPERDAY;
943        break;
944
945    case MONTH_NTH_DAY_OF_WEEK:
946        /*
947        ** Mm.n.d - nth "dth day" of month m.
948        */
949        value = janfirst;
950        for (i = 0; i < rulep->r_mon - 1; ++i)
951            value += mon_lengths[leapyear][i] * SECSPERDAY;
952
953        /*
954        ** Use Zeller's Congruence to get day-of-week of first day of
955        ** month.
956        */
957        m1 = (rulep->r_mon + 9) % 12 + 1;
958        yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
959        yy1 = yy0 / 100;
960        yy2 = yy0 % 100;
961        dow = ((26 * m1 - 2) / 10 +
962            1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
963        if (dow < 0)
964            dow += DAYSPERWEEK;
965
966        /*
967        ** "dow" is the day-of-week of the first day of the month. Get
968        ** the day-of-month (zero-origin) of the first "dow" day of the
969        ** month.
970        */
971        d = rulep->r_day - dow;
972        if (d < 0)
973            d += DAYSPERWEEK;
974        for (i = 1; i < rulep->r_week; ++i) {
975            if (d + DAYSPERWEEK >=
976                mon_lengths[leapyear][rulep->r_mon - 1])
977                    break;
978            d += DAYSPERWEEK;
979        }
980
981        /*
982        ** "d" is the day-of-month (zero-origin) of the day we want.
983        */
984        value += d * SECSPERDAY;
985        break;
986    }
987
988    /*
989    ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
990    ** question. To get the Epoch-relative time of the specified local
991    ** time on that day, add the transition time and the current offset
992    ** from UTC.
993    */
994    return value + rulep->r_time + offset;
995}
996
997/*
998** Given a POSIX section 8-style TZ string, fill in the rule tables as
999** appropriate.
1000*/
1001
1002static int
1003tzparse(name, sp, lastditch)
1004const char *            name;
1005register struct state * const   sp;
1006const int           lastditch;
1007{
1008    const char *            stdname;
1009    const char *            dstname;
1010    size_t              stdlen;
1011    size_t              dstlen;
1012    long                stdoffset;
1013    long                dstoffset;
1014    register time_t *       atp;
1015    register unsigned char *    typep;
1016    register char *         cp;
1017    register int            load_result;
1018
1019    INITIALIZE(dstname);
1020    stdname = name;
1021    if (lastditch) {
1022        stdlen = strlen(name);  /* length of standard zone name */
1023        name += stdlen;
1024        if (stdlen >= sizeof sp->chars)
1025            stdlen = (sizeof sp->chars) - 1;
1026        stdoffset = 0;
1027    } else {
1028        if (*name == '<') {
1029            name++;
1030            stdname = name;
1031            name = getqzname(name, '>');
1032            if (*name != '>')
1033                return (-1);
1034            stdlen = name - stdname;
1035            name++;
1036        } else {
1037            name = getzname(name);
1038            stdlen = name - stdname;
1039        }
1040        if (*name == '\0')
1041            return -1;
1042        name = getoffset(name, &stdoffset);
1043        if (name == NULL)
1044            return -1;
1045    }
1046    load_result = tzload(TZDEFRULES, sp, FALSE);
1047    if (load_result != 0)
1048        sp->leapcnt = 0;        /* so, we're off a little */
1049    sp->timecnt = 0;
1050    if (*name != '\0') {
1051        if (*name == '<') {
1052            dstname = ++name;
1053            name = getqzname(name, '>');
1054            if (*name != '>')
1055                return -1;
1056            dstlen = name - dstname;
1057            name++;
1058        } else {
1059            dstname = name;
1060            name = getzname(name);
1061            dstlen = name - dstname; /* length of DST zone name */
1062        }
1063        if (*name != '\0' && *name != ',' && *name != ';') {
1064            name = getoffset(name, &dstoffset);
1065            if (name == NULL)
1066                return -1;
1067        } else  dstoffset = stdoffset - SECSPERHOUR;
1068        if (*name == '\0' && load_result != 0)
1069            name = TZDEFRULESTRING;
1070        if (*name == ',' || *name == ';') {
1071            struct rule start;
1072            struct rule end;
1073            register int    year;
1074            register time_t janfirst;
1075            time_t      starttime;
1076            time_t      endtime;
1077
1078            ++name;
1079            if ((name = getrule(name, &start)) == NULL)
1080                return -1;
1081            if (*name++ != ',')
1082                return -1;
1083            if ((name = getrule(name, &end)) == NULL)
1084                return -1;
1085            if (*name != '\0')
1086                return -1;
1087            sp->typecnt = 2;    /* standard time and DST */
1088            /*
1089            ** Two transitions per year, from EPOCH_YEAR forward.
1090            */
1091            sp->ttis[0].tt_gmtoff = -dstoffset;
1092            sp->ttis[0].tt_isdst = 1;
1093            sp->ttis[0].tt_abbrind = stdlen + 1;
1094            sp->ttis[1].tt_gmtoff = -stdoffset;
1095            sp->ttis[1].tt_isdst = 0;
1096            sp->ttis[1].tt_abbrind = 0;
1097            atp = sp->ats;
1098            typep = sp->types;
1099            janfirst = 0;
1100            for (year = EPOCH_YEAR;
1101                sp->timecnt + 2 <= TZ_MAX_TIMES;
1102                ++year) {
1103                    time_t  newfirst;
1104
1105                starttime = transtime(janfirst, year, &start,
1106                    stdoffset);
1107                endtime = transtime(janfirst, year, &end,
1108                    dstoffset);
1109                if (starttime > endtime) {
1110                    *atp++ = endtime;
1111                    *typep++ = 1;   /* DST ends */
1112                    *atp++ = starttime;
1113                    *typep++ = 0;   /* DST begins */
1114                } else {
1115                    *atp++ = starttime;
1116                    *typep++ = 0;   /* DST begins */
1117                    *atp++ = endtime;
1118                    *typep++ = 1;   /* DST ends */
1119                }
1120                sp->timecnt += 2;
1121                newfirst = janfirst;
1122                newfirst += year_lengths[isleap(year)] *
1123                    SECSPERDAY;
1124                if (newfirst <= janfirst)
1125                    break;
1126                janfirst = newfirst;
1127            }
1128        } else {
1129            register long   theirstdoffset;
1130            register long   theirdstoffset;
1131            register long   theiroffset;
1132            register int    isdst;
1133            register int    i;
1134            register int    j;
1135
1136            if (*name != '\0')
1137                return -1;
1138            /*
1139            ** Initial values of theirstdoffset and theirdstoffset.
1140            */
1141            theirstdoffset = 0;
1142            for (i = 0; i < sp->timecnt; ++i) {
1143                j = sp->types[i];
1144                if (!sp->ttis[j].tt_isdst) {
1145                    theirstdoffset =
1146                        -sp->ttis[j].tt_gmtoff;
1147                    break;
1148                }
1149            }
1150            theirdstoffset = 0;
1151            for (i = 0; i < sp->timecnt; ++i) {
1152                j = sp->types[i];
1153                if (sp->ttis[j].tt_isdst) {
1154                    theirdstoffset =
1155                        -sp->ttis[j].tt_gmtoff;
1156                    break;
1157                }
1158            }
1159            /*
1160            ** Initially we're assumed to be in standard time.
1161            */
1162            isdst = FALSE;
1163            theiroffset = theirstdoffset;
1164            /*
1165            ** Now juggle transition times and types
1166            ** tracking offsets as you do.
1167            */
1168            for (i = 0; i < sp->timecnt; ++i) {
1169                j = sp->types[i];
1170                sp->types[i] = sp->ttis[j].tt_isdst;
1171                if (sp->ttis[j].tt_ttisgmt) {
1172                    /* No adjustment to transition time */
1173                } else {
1174                    /*
1175                    ** If summer time is in effect, and the
1176                    ** transition time was not specified as
1177                    ** standard time, add the summer time
1178                    ** offset to the transition time;
1179                    ** otherwise, add the standard time
1180                    ** offset to the transition time.
1181                    */
1182                    /*
1183                    ** Transitions from DST to DDST
1184                    ** will effectively disappear since
1185                    ** POSIX provides for only one DST
1186                    ** offset.
1187                    */
1188                    if (isdst && !sp->ttis[j].tt_ttisstd) {
1189                        sp->ats[i] += dstoffset -
1190                            theirdstoffset;
1191                    } else {
1192                        sp->ats[i] += stdoffset -
1193                            theirstdoffset;
1194                    }
1195                }
1196                theiroffset = -sp->ttis[j].tt_gmtoff;
1197                if (sp->ttis[j].tt_isdst)
1198                    theirdstoffset = theiroffset;
1199                else    theirstdoffset = theiroffset;
1200            }
1201            /*
1202            ** Finally, fill in ttis.
1203            ** ttisstd and ttisgmt need not be handled.
1204            */
1205            sp->ttis[0].tt_gmtoff = -stdoffset;
1206            sp->ttis[0].tt_isdst = FALSE;
1207            sp->ttis[0].tt_abbrind = 0;
1208            sp->ttis[1].tt_gmtoff = -dstoffset;
1209            sp->ttis[1].tt_isdst = TRUE;
1210            sp->ttis[1].tt_abbrind = stdlen + 1;
1211            sp->typecnt = 2;
1212        }
1213    } else {
1214        dstlen = 0;
1215        sp->typecnt = 1;        /* only standard time */
1216        sp->timecnt = 0;
1217        sp->ttis[0].tt_gmtoff = -stdoffset;
1218        sp->ttis[0].tt_isdst = 0;
1219        sp->ttis[0].tt_abbrind = 0;
1220    }
1221    sp->charcnt = stdlen + 1;
1222    if (dstlen != 0)
1223        sp->charcnt += dstlen + 1;
1224    if ((size_t) sp->charcnt > sizeof sp->chars)
1225        return -1;
1226    cp = sp->chars;
1227    (void) strncpy(cp, stdname, stdlen);
1228    cp += stdlen;
1229    *cp++ = '\0';
1230    if (dstlen != 0) {
1231        (void) strncpy(cp, dstname, dstlen);
1232        *(cp + dstlen) = '\0';
1233    }
1234    return 0;
1235}
1236
1237static void
1238gmtload(sp)
1239struct state * const    sp;
1240{
1241    if (tzload(gmt, sp, TRUE) != 0)
1242        (void) tzparse(gmt, sp, TRUE);
1243}
1244
1245static void
1246tzsetwall P((void))
1247{
1248    if (lcl_is_set < 0)
1249        return;
1250    lcl_is_set = -1;
1251
1252#ifdef ALL_STATE
1253    if (lclptr == NULL) {
1254        lclptr = (struct state *) malloc(sizeof *lclptr);
1255        if (lclptr == NULL) {
1256            settzname();    /* all we can do */
1257            return;
1258        }
1259    }
1260#endif /* defined ALL_STATE */
1261    if (tzload((char *) NULL, lclptr, TRUE) != 0)
1262        gmtload(lclptr);
1263    settzname();
1264}
1265
1266static void
1267tzset_locked P((void))
1268{
1269    register const char *   name = NULL;
1270    static char buf[PROP_VALUE_MAX];
1271
1272    name = getenv("TZ");
1273
1274    // try the "persist.sys.timezone" system property first
1275    if (name == NULL && __system_property_get("persist.sys.timezone", buf) > 0)
1276        name = buf;
1277
1278    if (name == NULL) {
1279        tzsetwall();
1280        return;
1281    }
1282
1283    if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0)
1284        return;
1285    lcl_is_set = strlen(name) < sizeof lcl_TZname;
1286    if (lcl_is_set)
1287        (void) strcpy(lcl_TZname, name);
1288
1289#ifdef ALL_STATE
1290    if (lclptr == NULL) {
1291        lclptr = (struct state *) malloc(sizeof *lclptr);
1292        if (lclptr == NULL) {
1293            settzname();    /* all we can do */
1294            return;
1295        }
1296    }
1297#endif /* defined ALL_STATE */
1298    if (*name == '\0') {
1299        /*
1300        ** User wants it fast rather than right.
1301        */
1302        lclptr->leapcnt = 0;        /* so, we're off a little */
1303        lclptr->timecnt = 0;
1304        lclptr->typecnt = 0;
1305        lclptr->ttis[0].tt_isdst = 0;
1306        lclptr->ttis[0].tt_gmtoff = 0;
1307        lclptr->ttis[0].tt_abbrind = 0;
1308        (void) strcpy(lclptr->chars, gmt);
1309    } else if (tzload(name, lclptr, TRUE) != 0)
1310        if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
1311            (void) gmtload(lclptr);
1312    settzname();
1313}
1314
1315void
1316tzset P((void))
1317{
1318    _tzLock();
1319    tzset_locked();
1320    _tzUnlock();
1321}
1322
1323/*
1324** The easy way to behave "as if no library function calls" localtime
1325** is to not call it--so we drop its guts into "localsub", which can be
1326** freely called. (And no, the PANS doesn't require the above behavior--
1327** but it *is* desirable.)
1328**
1329** The unused offset argument is for the benefit of mktime variants.
1330*/
1331
1332/*ARGSUSED*/
1333static struct tm *
1334localsub(timep, offset, tmp)
1335const time_t * const    timep;
1336const long      offset;
1337struct tm * const   tmp;
1338{
1339    register struct state *     sp;
1340    register const struct ttinfo *  ttisp;
1341    register int            i;
1342    register struct tm *        result;
1343    const time_t            t = *timep;
1344
1345    sp = lclptr;
1346#ifdef ALL_STATE
1347    if (sp == NULL)
1348        return gmtsub(timep, offset, tmp);
1349#endif /* defined ALL_STATE */
1350    if ((sp->goback && t < sp->ats[0]) ||
1351        (sp->goahead && t > sp->ats[sp->timecnt - 1])) {
1352            time_t          newt = t;
1353            register time_t     seconds;
1354            register time_t     tcycles;
1355            register int_fast64_t   icycles;
1356
1357            if (t < sp->ats[0])
1358                seconds = sp->ats[0] - t;
1359            else    seconds = t - sp->ats[sp->timecnt - 1];
1360            --seconds;
1361            tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
1362            ++tcycles;
1363            icycles = tcycles;
1364            if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
1365                return NULL;
1366            seconds = icycles;
1367            seconds *= YEARSPERREPEAT;
1368            seconds *= AVGSECSPERYEAR;
1369            if (t < sp->ats[0])
1370                newt += seconds;
1371            else    newt -= seconds;
1372            if (newt < sp->ats[0] ||
1373                newt > sp->ats[sp->timecnt - 1])
1374                    return NULL;    /* "cannot happen" */
1375            result = localsub(&newt, offset, tmp);
1376            if (result == tmp) {
1377                register time_t newy;
1378
1379                newy = tmp->tm_year;
1380                if (t < sp->ats[0])
1381                    newy -= icycles * YEARSPERREPEAT;
1382                else    newy += icycles * YEARSPERREPEAT;
1383                tmp->tm_year = newy;
1384                if (tmp->tm_year != newy)
1385                    return NULL;
1386            }
1387            return result;
1388    }
1389    if (sp->timecnt == 0 || t < sp->ats[0]) {
1390        i = 0;
1391        while (sp->ttis[i].tt_isdst)
1392            if (++i >= sp->typecnt) {
1393                i = 0;
1394                break;
1395            }
1396    } else {
1397        register int    lo = 1;
1398        register int    hi = sp->timecnt;
1399
1400        while (lo < hi) {
1401            register int    mid = (lo + hi) >> 1;
1402
1403            if (t < sp->ats[mid])
1404                hi = mid;
1405            else    lo = mid + 1;
1406        }
1407        i = (int) sp->types[lo - 1];
1408    }
1409    ttisp = &sp->ttis[i];
1410    /*
1411    ** To get (wrong) behavior that's compatible with System V Release 2.0
1412    ** you'd replace the statement below with
1413    **  t += ttisp->tt_gmtoff;
1414    **  timesub(&t, 0L, sp, tmp);
1415    */
1416    result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1417    tmp->tm_isdst = ttisp->tt_isdst;
1418    tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1419#ifdef TM_ZONE
1420    tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1421#endif /* defined TM_ZONE */
1422    return result;
1423}
1424
1425struct tm *
1426localtime(timep)
1427const time_t * const    timep;
1428{
1429    return localtime_r(timep, &tmGlobal);
1430}
1431
1432/*
1433** Re-entrant version of localtime.
1434*/
1435
1436struct tm *
1437localtime_r(timep, tmp)
1438const time_t * const    timep;
1439struct tm *     tmp;
1440{
1441    struct tm*  result;
1442
1443    _tzLock();
1444    tzset_locked();
1445    result = localsub(timep, 0L, tmp);
1446    _tzUnlock();
1447
1448    return result;
1449}
1450
1451/*
1452** gmtsub is to gmtime as localsub is to localtime.
1453*/
1454
1455static struct tm *
1456gmtsub(timep, offset, tmp)
1457const time_t * const    timep;
1458const long      offset;
1459struct tm * const   tmp;
1460{
1461    register struct tm *    result;
1462
1463    if (!gmt_is_set) {
1464        gmt_is_set = TRUE;
1465#ifdef ALL_STATE
1466        gmtptr = (struct state *) malloc(sizeof *gmtptr);
1467        if (gmtptr != NULL)
1468#endif /* defined ALL_STATE */
1469            gmtload(gmtptr);
1470    }
1471    result = timesub(timep, offset, gmtptr, tmp);
1472#ifdef TM_ZONE
1473    /*
1474    ** Could get fancy here and deliver something such as
1475    ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
1476    ** but this is no time for a treasure hunt.
1477    */
1478    if (offset != 0)
1479        tmp->TM_ZONE = wildabbr;
1480    else {
1481#ifdef ALL_STATE
1482        if (gmtptr == NULL)
1483            tmp->TM_ZONE = gmt;
1484        else    tmp->TM_ZONE = gmtptr->chars;
1485#endif /* defined ALL_STATE */
1486#ifndef ALL_STATE
1487        tmp->TM_ZONE = gmtptr->chars;
1488#endif /* State Farm */
1489    }
1490#endif /* defined TM_ZONE */
1491    return result;
1492}
1493
1494struct tm *
1495gmtime(timep)
1496const time_t * const    timep;
1497{
1498    return gmtime_r(timep, &tmGlobal);
1499}
1500
1501/*
1502* Re-entrant version of gmtime.
1503*/
1504
1505struct tm *
1506gmtime_r(timep, tmp)
1507const time_t * const    timep;
1508struct tm *     tmp;
1509{
1510    struct tm*  result;
1511
1512    _tzLock();
1513    result = gmtsub(timep, 0L, tmp);
1514    _tzUnlock();
1515
1516    return result;
1517}
1518
1519#ifdef STD_INSPIRED
1520#if 0 /* disabled because there is no good documentation for this function */
1521struct tm *
1522offtime(timep, offset)
1523const time_t * const    timep;
1524const long      offset;
1525{
1526    return gmtsub(timep, offset, &tmGlobal);
1527}
1528#endif /* 0 */
1529#endif /* defined STD_INSPIRED */
1530
1531/*
1532** Return the number of leap years through the end of the given year
1533** where, to make the math easy, the answer for year zero is defined as zero.
1534*/
1535
1536static int
1537leaps_thru_end_of(y)
1538register const int  y;
1539{
1540    return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
1541        -(leaps_thru_end_of(-(y + 1)) + 1);
1542}
1543
1544static struct tm *
1545timesub(timep, offset, sp, tmp)
1546const time_t * const            timep;
1547const long              offset;
1548register const struct state * const sp;
1549register struct tm * const      tmp;
1550{
1551    register const struct lsinfo *  lp;
1552    register time_t         tdays;
1553    register int            idays;  /* unsigned would be so 2003 */
1554    register long           rem;
1555    int             y;
1556    register const int *        ip;
1557    register long           corr;
1558    register int            hit;
1559    register int            i;
1560
1561    corr = 0;
1562    hit = 0;
1563#ifdef ALL_STATE
1564    i = (sp == NULL) ? 0 : sp->leapcnt;
1565#endif /* defined ALL_STATE */
1566#ifndef ALL_STATE
1567    i = sp->leapcnt;
1568#endif /* State Farm */
1569    while (--i >= 0) {
1570        lp = &sp->lsis[i];
1571        if (*timep >= lp->ls_trans) {
1572            if (*timep == lp->ls_trans) {
1573                hit = ((i == 0 && lp->ls_corr > 0) ||
1574                    lp->ls_corr > sp->lsis[i - 1].ls_corr);
1575                if (hit)
1576                    while (i > 0 &&
1577                        sp->lsis[i].ls_trans ==
1578                        sp->lsis[i - 1].ls_trans + 1 &&
1579                        sp->lsis[i].ls_corr ==
1580                        sp->lsis[i - 1].ls_corr + 1) {
1581                            ++hit;
1582                            --i;
1583                    }
1584            }
1585            corr = lp->ls_corr;
1586            break;
1587        }
1588    }
1589    y = EPOCH_YEAR;
1590    tdays = *timep / SECSPERDAY;
1591    rem = *timep - tdays * SECSPERDAY;
1592    while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
1593        int     newy;
1594        register time_t tdelta;
1595        register int    idelta;
1596        register int    leapdays;
1597
1598        tdelta = tdays / DAYSPERLYEAR;
1599        idelta = tdelta;
1600        if (tdelta - idelta >= 1 || idelta - tdelta >= 1)
1601            return NULL;
1602        if (idelta == 0)
1603            idelta = (tdays < 0) ? -1 : 1;
1604        newy = y;
1605        if (increment_overflow(&newy, idelta))
1606            return NULL;
1607        leapdays = leaps_thru_end_of(newy - 1) -
1608            leaps_thru_end_of(y - 1);
1609        tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
1610        tdays -= leapdays;
1611        y = newy;
1612    }
1613    {
1614        register long   seconds;
1615
1616        seconds = tdays * SECSPERDAY + 0.5;
1617        tdays = seconds / SECSPERDAY;
1618        rem += seconds - tdays * SECSPERDAY;
1619    }
1620    /*
1621    ** Given the range, we can now fearlessly cast...
1622    */
1623    idays = tdays;
1624    rem += offset - corr;
1625    while (rem < 0) {
1626        rem += SECSPERDAY;
1627        --idays;
1628    }
1629    while (rem >= SECSPERDAY) {
1630        rem -= SECSPERDAY;
1631        ++idays;
1632    }
1633    while (idays < 0) {
1634        if (increment_overflow(&y, -1))
1635            return NULL;
1636        idays += year_lengths[isleap(y)];
1637    }
1638    while (idays >= year_lengths[isleap(y)]) {
1639        idays -= year_lengths[isleap(y)];
1640        if (increment_overflow(&y, 1))
1641            return NULL;
1642    }
1643    tmp->tm_year = y;
1644    if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
1645        return NULL;
1646    tmp->tm_yday = idays;
1647    /*
1648    ** The "extra" mods below avoid overflow problems.
1649    */
1650    tmp->tm_wday = EPOCH_WDAY +
1651        ((y - EPOCH_YEAR) % DAYSPERWEEK) *
1652        (DAYSPERNYEAR % DAYSPERWEEK) +
1653        leaps_thru_end_of(y - 1) -
1654        leaps_thru_end_of(EPOCH_YEAR - 1) +
1655        idays;
1656    tmp->tm_wday %= DAYSPERWEEK;
1657    if (tmp->tm_wday < 0)
1658        tmp->tm_wday += DAYSPERWEEK;
1659    tmp->tm_hour = (int) (rem / SECSPERHOUR);
1660    rem %= SECSPERHOUR;
1661    tmp->tm_min = (int) (rem / SECSPERMIN);
1662    /*
1663    ** A positive leap second requires a special
1664    ** representation. This uses "... ??:59:60" et seq.
1665    */
1666    tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1667    ip = mon_lengths[isleap(y)];
1668    for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
1669        idays -= ip[tmp->tm_mon];
1670    tmp->tm_mday = (int) (idays + 1);
1671    tmp->tm_isdst = 0;
1672#ifdef TM_GMTOFF
1673    tmp->TM_GMTOFF = offset;
1674#endif /* defined TM_GMTOFF */
1675    return tmp;
1676}
1677
1678char *
1679ctime(timep)
1680const time_t * const    timep;
1681{
1682/*
1683** Section 4.12.3.2 of X3.159-1989 requires that
1684**  The ctime function converts the calendar time pointed to by timer
1685**  to local time in the form of a string. It is equivalent to
1686**      asctime(localtime(timer))
1687*/
1688    return asctime(localtime(timep));
1689}
1690
1691char *
1692ctime_r(timep, buf)
1693const time_t * const    timep;
1694char *          buf;
1695{
1696    struct tm   mytm;
1697
1698    return asctime_r(localtime_r(timep, &mytm), buf);
1699}
1700
1701/*
1702** Adapted from code provided by Robert Elz, who writes:
1703**  The "best" way to do mktime I think is based on an idea of Bob
1704**  Kridle's (so its said...) from a long time ago.
1705**  It does a binary search of the time_t space. Since time_t's are
1706**  just 32 bits, its a max of 32 iterations (even at 64 bits it
1707**  would still be very reasonable).
1708*/
1709
1710#ifndef WRONG
1711#define WRONG   (-1)
1712#endif /* !defined WRONG */
1713
1714/*
1715** Simplified normalize logic courtesy Paul Eggert.
1716*/
1717
1718static int
1719increment_overflow(number, delta)
1720int *   number;
1721int delta;
1722{
1723    unsigned  number0 = (unsigned)*number;
1724    unsigned  number1 = (unsigned)(number0 + delta);
1725
1726    *number = (int)number1;
1727
1728    if (delta >= 0) {
1729        return ((int)number1 < (int)number0);
1730    } else {
1731        return ((int)number1 > (int)number0);
1732    }
1733}
1734
1735static int
1736long_increment_overflow(number, delta)
1737long *  number;
1738int delta;
1739{
1740    unsigned long  number0 = (unsigned long)*number;
1741    unsigned long  number1 = (unsigned long)(number0 + delta);
1742
1743    *number = (long)number1;
1744
1745    if (delta >= 0) {
1746        return ((long)number1 < (long)number0);
1747    } else {
1748        return ((long)number1 > (long)number0);
1749    }
1750}
1751
1752static int
1753normalize_overflow(tensptr, unitsptr, base)
1754int * const tensptr;
1755int * const unitsptr;
1756const int   base;
1757{
1758    register int    tensdelta;
1759
1760    tensdelta = (*unitsptr >= 0) ?
1761        (*unitsptr / base) :
1762        (-1 - (-1 - *unitsptr) / base);
1763    *unitsptr -= tensdelta * base;
1764    return increment_overflow(tensptr, tensdelta);
1765}
1766
1767static int
1768long_normalize_overflow(tensptr, unitsptr, base)
1769long * const    tensptr;
1770int * const unitsptr;
1771const int   base;
1772{
1773    register int    tensdelta;
1774
1775    tensdelta = (*unitsptr >= 0) ?
1776        (*unitsptr / base) :
1777        (-1 - (-1 - *unitsptr) / base);
1778    *unitsptr -= tensdelta * base;
1779    return long_increment_overflow(tensptr, tensdelta);
1780}
1781
1782static int
1783tmcomp(atmp, btmp)
1784register const struct tm * const atmp;
1785register const struct tm * const btmp;
1786{
1787    register int    result;
1788
1789    if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1790        (result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1791        (result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1792        (result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1793        (result = (atmp->tm_min - btmp->tm_min)) == 0)
1794            result = atmp->tm_sec - btmp->tm_sec;
1795    return result;
1796}
1797
1798static time_t
1799time2sub(tmp, funcp, offset, okayp, do_norm_secs)
1800struct tm * const   tmp;
1801struct tm * (* const    funcp) P((const time_t*, long, struct tm*));
1802const long      offset;
1803int * const     okayp;
1804const int       do_norm_secs;
1805{
1806    register const struct state *   sp;
1807    register int            dir;
1808    register int            i, j;
1809    register int            saved_seconds;
1810    register long           li;
1811    register time_t         lo;
1812    register time_t         hi;
1813    long                y;
1814    time_t              newt;
1815    time_t              t;
1816    struct tm           yourtm, mytm;
1817
1818    *okayp = FALSE;
1819    yourtm = *tmp;
1820    if (do_norm_secs) {
1821        if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
1822            SECSPERMIN))
1823                return WRONG;
1824    }
1825    if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1826        return WRONG;
1827    if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1828        return WRONG;
1829    y = yourtm.tm_year;
1830    if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR))
1831        return WRONG;
1832    /*
1833    ** Turn y into an actual year number for now.
1834    ** It is converted back to an offset from TM_YEAR_BASE later.
1835    */
1836    if (long_increment_overflow(&y, TM_YEAR_BASE))
1837        return WRONG;
1838    while (yourtm.tm_mday <= 0) {
1839        if (long_increment_overflow(&y, -1))
1840            return WRONG;
1841        li = y + (1 < yourtm.tm_mon);
1842        yourtm.tm_mday += year_lengths[isleap(li)];
1843    }
1844    while (yourtm.tm_mday > DAYSPERLYEAR) {
1845        li = y + (1 < yourtm.tm_mon);
1846        yourtm.tm_mday -= year_lengths[isleap(li)];
1847        if (long_increment_overflow(&y, 1))
1848            return WRONG;
1849    }
1850    for ( ; ; ) {
1851        i = mon_lengths[isleap(y)][yourtm.tm_mon];
1852        if (yourtm.tm_mday <= i)
1853            break;
1854        yourtm.tm_mday -= i;
1855        if (++yourtm.tm_mon >= MONSPERYEAR) {
1856            yourtm.tm_mon = 0;
1857            if (long_increment_overflow(&y, 1))
1858                return WRONG;
1859        }
1860    }
1861    if (long_increment_overflow(&y, -TM_YEAR_BASE))
1862        return WRONG;
1863    yourtm.tm_year = y;
1864    if (yourtm.tm_year != y)
1865        return WRONG;
1866    if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
1867        saved_seconds = 0;
1868    else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
1869        /*
1870        ** We can't set tm_sec to 0, because that might push the
1871        ** time below the minimum representable time.
1872        ** Set tm_sec to 59 instead.
1873        ** This assumes that the minimum representable time is
1874        ** not in the same minute that a leap second was deleted from,
1875        ** which is a safer assumption than using 58 would be.
1876        */
1877        if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1878            return WRONG;
1879        saved_seconds = yourtm.tm_sec;
1880        yourtm.tm_sec = SECSPERMIN - 1;
1881    } else {
1882        saved_seconds = yourtm.tm_sec;
1883        yourtm.tm_sec = 0;
1884    }
1885    /*
1886    ** Do a binary search (this works whatever time_t's type is).
1887    */
1888    if (!TYPE_SIGNED(time_t)) {
1889        lo = 0;
1890        hi = lo - 1;
1891    } else if (!TYPE_INTEGRAL(time_t)) {
1892        if (sizeof(time_t) > sizeof(float))
1893            hi = (time_t) DBL_MAX;
1894        else    hi = (time_t) FLT_MAX;
1895        lo = -hi;
1896    } else {
1897        lo = 1;
1898        for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
1899            lo *= 2;
1900        hi = -(lo + 1);
1901    }
1902    for ( ; ; ) {
1903        t = lo / 2 + hi / 2;
1904        if (t < lo)
1905            t = lo;
1906        else if (t > hi)
1907            t = hi;
1908        if ((*funcp)(&t, offset, &mytm) == NULL) {
1909            /*
1910            ** Assume that t is too extreme to be represented in
1911            ** a struct tm; arrange things so that it is less
1912            ** extreme on the next pass.
1913            */
1914            dir = (t > 0) ? 1 : -1;
1915        } else  dir = tmcomp(&mytm, &yourtm);
1916        if (dir != 0) {
1917            if (t == lo) {
1918                if (t == TIME_T_MAX)
1919                    return WRONG;
1920                ++t;
1921                ++lo;
1922            } else if (t == hi) {
1923                if (t == TIME_T_MIN)
1924                    return WRONG;
1925                --t;
1926                --hi;
1927            }
1928            if (lo > hi)
1929                return WRONG;
1930            if (dir > 0)
1931                hi = t;
1932            else    lo = t;
1933            continue;
1934        }
1935        if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1936            break;
1937        /*
1938        ** Right time, wrong type.
1939        ** Hunt for right time, right type.
1940        ** It's okay to guess wrong since the guess
1941        ** gets checked.
1942        */
1943        /*
1944        ** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
1945        */
1946        sp = (const struct state *)
1947            (((void *) funcp == (void *) localsub) ?
1948            lclptr : gmtptr);
1949#ifdef ALL_STATE
1950        if (sp == NULL)
1951            return WRONG;
1952#endif /* defined ALL_STATE */
1953        for (i = sp->typecnt - 1; i >= 0; --i) {
1954            if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1955                continue;
1956            for (j = sp->typecnt - 1; j >= 0; --j) {
1957                if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1958                    continue;
1959                newt = t + sp->ttis[j].tt_gmtoff -
1960                    sp->ttis[i].tt_gmtoff;
1961                if ((*funcp)(&newt, offset, &mytm) == NULL)
1962                    continue;
1963                if (tmcomp(&mytm, &yourtm) != 0)
1964                    continue;
1965                if (mytm.tm_isdst != yourtm.tm_isdst)
1966                    continue;
1967                /*
1968                ** We have a match.
1969                */
1970                t = newt;
1971                goto label;
1972            }
1973        }
1974        return WRONG;
1975    }
1976label:
1977    newt = t + saved_seconds;
1978    if ((newt < t) != (saved_seconds < 0))
1979        return WRONG;
1980    t = newt;
1981    if ((*funcp)(&t, offset, tmp))
1982        *okayp = TRUE;
1983    return t;
1984}
1985
1986static time_t
1987time2(tmp, funcp, offset, okayp)
1988struct tm * const   tmp;
1989struct tm * (* const    funcp) P((const time_t*, long, struct tm*));
1990const long      offset;
1991int * const     okayp;
1992{
1993    time_t  t;
1994
1995    /*
1996    ** First try without normalization of seconds
1997    ** (in case tm_sec contains a value associated with a leap second).
1998    ** If that fails, try with normalization of seconds.
1999    */
2000    t = time2sub(tmp, funcp, offset, okayp, FALSE);
2001    return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
2002}
2003
2004static time_t
2005time1(tmp, funcp, offset)
2006struct tm * const   tmp;
2007struct tm * (* const    funcp) P((const time_t *, long, struct tm *));
2008const long      offset;
2009{
2010    register time_t         t;
2011    register const struct state *   sp;
2012    register int            samei, otheri;
2013    register int            sameind, otherind;
2014    register int            i;
2015    register int            nseen;
2016    int             seen[TZ_MAX_TYPES];
2017    int             types[TZ_MAX_TYPES];
2018    int             okay;
2019
2020    if (tmp->tm_isdst > 1)
2021        tmp->tm_isdst = 1;
2022    t = time2(tmp, funcp, offset, &okay);
2023#ifdef PCTS
2024    /*
2025    ** PCTS code courtesy Grant Sullivan.
2026    */
2027    if (okay)
2028        return t;
2029    if (tmp->tm_isdst < 0)
2030        tmp->tm_isdst = 0;  /* reset to std and try again */
2031#endif /* defined PCTS */
2032#ifndef PCTS
2033    if (okay || tmp->tm_isdst < 0)
2034        return t;
2035#endif /* !defined PCTS */
2036    /*
2037    ** We're supposed to assume that somebody took a time of one type
2038    ** and did some math on it that yielded a "struct tm" that's bad.
2039    ** We try to divine the type they started from and adjust to the
2040    ** type they need.
2041    */
2042    /*
2043    ** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
2044    */
2045    sp = (const struct state *) (((void *) funcp == (void *) localsub) ?
2046        lclptr : gmtptr);
2047#ifdef ALL_STATE
2048    if (sp == NULL)
2049        return WRONG;
2050#endif /* defined ALL_STATE */
2051    for (i = 0; i < sp->typecnt; ++i)
2052        seen[i] = FALSE;
2053    nseen = 0;
2054    for (i = sp->timecnt - 1; i >= 0; --i)
2055        if (!seen[sp->types[i]]) {
2056            seen[sp->types[i]] = TRUE;
2057            types[nseen++] = sp->types[i];
2058        }
2059    for (sameind = 0; sameind < nseen; ++sameind) {
2060        samei = types[sameind];
2061        if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
2062            continue;
2063        for (otherind = 0; otherind < nseen; ++otherind) {
2064            otheri = types[otherind];
2065            if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
2066                continue;
2067            tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
2068                    sp->ttis[samei].tt_gmtoff;
2069            tmp->tm_isdst = !tmp->tm_isdst;
2070            t = time2(tmp, funcp, offset, &okay);
2071            if (okay)
2072                return t;
2073            tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
2074                    sp->ttis[samei].tt_gmtoff;
2075            tmp->tm_isdst = !tmp->tm_isdst;
2076        }
2077    }
2078    return WRONG;
2079}
2080
2081time_t
2082mktime(tmp)
2083struct tm * const   tmp;
2084{
2085    time_t  result;
2086    _tzLock();
2087    tzset_locked();
2088    result = time1(tmp, localsub, 0L);
2089    _tzUnlock();
2090    return result;
2091}
2092
2093#ifdef STD_INSPIRED
2094
2095time_t
2096timelocal(tmp)
2097struct tm * const   tmp;
2098{
2099    tmp->tm_isdst = -1; /* in case it wasn't initialized */
2100    return mktime(tmp);
2101}
2102
2103time_t
2104timegm(tmp)
2105struct tm * const   tmp;
2106{
2107    time_t  result;
2108
2109    tmp->tm_isdst = 0;
2110    _tzLock();
2111    result = time1(tmp, gmtsub, 0L);
2112    _tzUnlock();
2113
2114    return result;
2115}
2116
2117#if 0 /* disable due to lack of clear documentation on this function */
2118time_t
2119timeoff(tmp, offset)
2120struct tm * const   tmp;
2121const long      offset;
2122{
2123    time_t  result;
2124
2125    tmp->tm_isdst = 0;
2126    _tzLock();
2127    result = time1(tmp, gmtsub, offset);
2128    _tzUnlock();
2129
2130    return result;
2131}
2132#endif /* 0 */
2133
2134#endif /* defined STD_INSPIRED */
2135
2136#ifdef CMUCS
2137
2138/*
2139** The following is supplied for compatibility with
2140** previous versions of the CMUCS runtime library.
2141*/
2142
2143long
2144gtime(tmp)
2145struct tm * const   tmp;
2146{
2147    const time_t    t = mktime(tmp);
2148
2149    if (t == WRONG)
2150        return -1;
2151    return t;
2152}
2153
2154#endif /* defined CMUCS */
2155
2156/*
2157** XXX--is the below the right way to conditionalize??
2158*/
2159
2160#ifdef STD_INSPIRED
2161
2162/*
2163** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
2164** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
2165** is not the case if we are accounting for leap seconds.
2166** So, we provide the following conversion routines for use
2167** when exchanging timestamps with POSIX conforming systems.
2168*/
2169
2170static long
2171leapcorr(timep)
2172time_t *    timep;
2173{
2174    register struct state *     sp;
2175    register struct lsinfo *    lp;
2176    register int            i;
2177
2178    sp = lclptr;
2179    i = sp->leapcnt;
2180    while (--i >= 0) {
2181        lp = &sp->lsis[i];
2182        if (*timep >= lp->ls_trans)
2183            return lp->ls_corr;
2184    }
2185    return 0;
2186}
2187
2188time_t
2189time2posix(t)
2190time_t  t;
2191{
2192    tzset();
2193    return t - leapcorr(&t);
2194}
2195
2196time_t
2197posix2time(t)
2198time_t  t;
2199{
2200    time_t  x;
2201    time_t  y;
2202
2203    tzset();
2204    /*
2205    ** For a positive leap second hit, the result
2206    ** is not unique. For a negative leap second
2207    ** hit, the corresponding time doesn't exist,
2208    ** so we return an adjacent second.
2209    */
2210    x = t + leapcorr(&t);
2211    y = x - leapcorr(&x);
2212    if (y < t) {
2213        do {
2214            x++;
2215            y = x - leapcorr(&x);
2216        } while (y < t);
2217        if (t != y)
2218            return x - 1;
2219    } else if (y > t) {
2220        do {
2221            --x;
2222            y = x - leapcorr(&x);
2223        } while (y > t);
2224        if (t != y)
2225            return x + 1;
2226    }
2227    return x;
2228}
2229
2230#endif /* defined STD_INSPIRED */
2231