reactos/lib/sdk/crt/time/ctime.c

   1
   2 // fix djdir
   3
   4 /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
   5 /* This file has been modified by DJ Delorie.  These modifications are
   6 ** Copyright (C) 1995 DJ Delorie, 24 Kirsten Ave, Rochester NH,
   7 ** 03867-2954, USA.
   8 */
   9
  10 /*
  11  * Copyright (c) 1987, 1989 Regents of the University of California.
  12  * All rights reserved.
  13  *
  14  * This code is derived from software contributed to Berkeley by
  15  * Arthur David Olson of the National Cancer Institute.
  16  *
  17  * Redistribution and use in source and binary forms are permitted provided
  18  * that: (1) source distributions retain this entire copyright notice and
  19  * comment, and (2) distributions including binaries display the following
  20  * acknowledgement:  ``This product includes software developed by the
  21  * University of California, Berkeley and its contributors'' in the
  22  * documentation or other materials provided with the distribution and in
  23  * all advertising materials mentioning features or use of this software.
  24  * Neither the name of the University nor the names of its contributors may
  25  * be used to endorse or promote products derived from this software without
  26  * specific prior written permission.
  27  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  28  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  29  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  30  */
  31
  32 /*
  33 ** Leap second handling from Bradley White (bww@k.gp.cs.cmu.edu).
  34 ** POSIX-style TZ environment variable handling from Guy Harris
  35 ** (guy@auspex.com).
  36 */
  37
  38 #include <precomp.h>
  39
  40 #include "tzfile.h"
  41 #include "posixrul.h"
  42
  43 #ifdef __cplusplus
  44 #define CPP_CONST const
  45 #else
  46 #define CPP_CONST
  47 #endif
  48
  49 #define P(s)        s
  50 #define alloc_size_t    size_t
  51 #define qsort_size_t    size_t
  52 #define fread_size_t    size_t
  53 #define fwrite_size_t   size_t
  54
  55 #define ACCESS_MODE O_RDONLY|O_BINARY
  56 #define OPEN_MODE   O_RDONLY|O_BINARY
  57
  58 /*
  59 ** Someone might make incorrect use of a time zone abbreviation:
  60 **  1.  They might reference tzname[0] before calling tzset (explicitly
  61 **      or implicitly).
  62 **  2.  They might reference tzname[1] before calling tzset (explicitly
  63 **      or implicitly).
  64 **  3.  They might reference tzname[1] after setting to a time zone
  65 **      in which Daylight Saving Time is never observed.
  66 **  4.  They might reference tzname[0] after setting to a time zone
  67 **      in which Standard Time is never observed.
  68 **  5.  They might reference tm.TM_ZONE after calling offtime.
  69 ** What's best to do in the above cases is open to debate;
  70 ** for now, we just set things up so that in any of the five cases
  71 ** WILDABBR is used.  Another possibility:  initialize tzname[0] to the
  72 ** string "tzname[0] used before set", and similarly for the other cases.
  73 ** And another:  initialize tzname[0] to "ERA", with an explanation in the
  74 ** manual page of what this "time zone abbreviation" means (doing this so
  75 ** that tzname[0] has the "normal" length of three characters).
  76 */
  77
  78 void _set_daylight_export(int);
  79 void _set_timezone_export(int);
  80
  81
  82 /* buffers must hold 64 characters! */
  83 static char TZ_NAME[64] = "PST";
  84 static char TZ_DST_NAME[64] = "PDT";
  85
  86 #ifndef TRUE
  87 #define TRUE        1
  88 #define FALSE       0
  89 #endif /* !defined TRUE */
  90
  91 static const char GMT[] = "GMT";
  92
  93 struct ttinfo {     /* time type information */
  94   long tt_gmtoff;   /* GMT offset in seconds */
  95   int tt_isdst;     /* used to set tm_isdst */
  96   int tt_abbrind;   /* abbreviation list index */
  97   int tt_ttisstd;   /* TRUE if transition is std time */
  98 };
  99
 100 struct lsinfo {     /* leap second information */
 101   time_t ls_trans;  /* transition time */
 102   long ls_corr;     /* correction to apply */
 103 };
 104
 105 struct state {
 106   int leapcnt;
 107   int timecnt;
 108   int typecnt;
 109   int charcnt;
 110   time_t ats[TZ_MAX_TIMES];
 111   unsigned char types[TZ_MAX_TIMES];
 112   struct ttinfo ttis[TZ_MAX_TYPES];
 113   char chars[(TZ_MAX_CHARS + 1 > sizeof GMT) ? TZ_MAX_CHARS + 1 : sizeof GMT];
 114   struct lsinfo lsis[TZ_MAX_LEAPS];
 115 };
 116
 117 struct rule {
 118   int r_type;       /* type of rule--see below */
 119   int r_day;        /* day number of rule */
 120   int r_week;       /* week number of rule */
 121   int r_mon;        /* month number of rule */
 122   long r_time;      /* transition time of rule */
 123 };
 124
 125 #define JULIAN_DAY      0   /* Jn - Julian day */
 126 #define DAY_OF_YEAR     1   /* n - day of year */
 127 #define MONTH_NTH_DAY_OF_WEEK   2   /* Mm.n.d - month, week, day of week */
 128
 129 /*
 130 ** Prototypes for static functions.
 131 */
 132 #if 0
 133 static long     detzcode P((const char * codep));
 134 static const char * getzname P((const char * strp));
 135 static const char * getnum P((const char * strp, int * nump, int min, int max));
 136 static const char * getsecs P((const char * strp, long * secsp));
 137 static const char * getoffset P((const char * strp, long * offsetp));
 138 static const char * getrule P((const char * strp, struct rule * rulep));
 139 static void     gmtload P((struct state * sp));
 140 static void     gmtsub P((const time_t * timep, long offset, struct tm * tmp));
 141 static void     localsub P((const time_t * timep, long offset, struct tm * tmp));
 142 static void     normalize P((int * tensptr, int * unitsptr, int base));
 143 static void     settzname P((void));
 144 static time_t   time1 P((struct tm * tmp, void (* funcp)(const time_t * CPP_CONST, const long, struct tm * CPP_CONST), long offset));
 145 static time_t   time2 P((struct tm *tmp, void (* funcp)(const time_t * CPP_CONST, const long, struct tm * CPP_CONST), long offset, int * okayp));
 146 static void     timesub P((const time_t * timep, long offset, const struct state * sp, struct tm * tmp));
 147 static int      tmcomp P((const struct tm * atmp, const struct tm * btmp));
 148 static time_t   transtime P((time_t janfirst, int year, const struct rule * rulep, long offset));
 149 static int      tzload P((const char * name, struct state * sp));
 150 static int      tzparse P((const char * name, struct state * sp, int lastditch));
 151 static void     tzsetwall(void);
 152
 153 #else
 154
 155 static const char * getnum(const char * strp, int * CPP_CONST nump, const int min, const int max);
 156 static void     timesub(const time_t * CPP_CONST timep, const long offset, const struct state * CPP_CONST sp, struct tm * CPP_CONST tmp);
 157 static time_t   transtime(const time_t janfirst, const int year, const struct rule * CPP_CONST rulep, const long offset);
 158 static void     tzsetwall(void);
 159
 160 #endif
 161
 162 #ifdef ALL_STATE
 163 static struct state *lclptr;
 164 static struct state *gmtptr;
 165 #endif /* defined ALL_STATE */
 166
 167 #ifndef ALL_STATE
 168 static struct state lclmem;
 169 static struct state gmtmem;
 170 #define lclptr (&lclmem)
 171 #define gmtptr (&gmtmem)
 172 #endif /* State Farm */
 173
 174 static int lcl_is_set;
 175 static int gmt_is_set;
 176
 177 char * _tzname[2] = {
 178   TZ_NAME,
 179   TZ_DST_NAME,
 180 };
 181
 182 static long
 183 detzcode(const char * CPP_CONST codep)
 184 {
 185   long result;
 186   int i;
 187
 188   result = 0;
 189   for (i = 0; i < 4; ++i)
 190     result = (result << 8) | (codep[i] & 0xff);
 191   return result;
 192 }
 193
 194 static void
 195 settzname(void)
 196 {
 197   const struct state * CPP_CONST sp = lclptr;
 198   int i;
 199
 200   _tzname[0] = TZ_NAME;
 201   _tzname[1] = TZ_DST_NAME;
 202 #ifdef ALL_STATE
 203   if (sp == NULL)
 204   {
 205     _tzname[0] = _tzname[1] = GMT;
 206     return;
 207   }
 208 #endif /* defined ALL_STATE */
 209   for (i = 0; i < sp->typecnt; ++i)
 210   {
 211     register const struct ttinfo * CPP_CONST ttisp = &sp->ttis[i];
 212
 213     _tzname[ttisp->tt_isdst] =
 214       (char *)&sp->chars[ttisp->tt_abbrind];
 215 #if 0
 216     if (ttisp->tt_isdst) {
 217       //_daylight = 1;
 218       _set_daylight_export(1);
 219     }
 220     if (i == 0 || !ttisp->tt_isdst) {
 221       //_timezone_dll = -(ttisp->tt_gmtoff);
 222       _set_timezone_export(-(ttisp->tt_gmtoff));
 223     }
 224     if (i == 0 || ttisp->tt_isdst) {
 225       _altzone = -(ttisp->tt_gmtoff);
 226     }
 227 #endif
 228   }
 229   /*
 230    ** And to get the latest zone names into tzname. . .
 231    */
 232   for (i = 0; i < sp->timecnt; ++i)
 233   {
 234     const struct ttinfo * CPP_CONST ttisp = &sp->ttis[sp->types[i]];
 235
 236     _tzname[ttisp->tt_isdst] = (char *)&sp->chars[ttisp->tt_abbrind];
 237   }
 238 }
 239
 240 static char* tzdir(void)
 241 {
 242   static char dir[80]={0}, *cp;
 243   if (dir[0] == 0)
 244   {
 245     if ((cp = getenv("TZDIR")))
 246     {
 247       strcpy(dir, cp);
 248     }
 249     else if ((cp = getenv("DJDIR")))
 250     {
 251       strcpy(dir, cp);
 252       strcat(dir, "/zoneinfo");
 253     }
 254     else
 255       strcpy(dir, "./");
 256   }
 257   return dir;
 258 }
 259
 260 static int tzload(const char* name, struct state* CPP_CONST sp)
 261 {
 262   const char * p;
 263   int i;
 264   int fid;
 265   char fullname[FILENAME_MAX + 1];
 266   const struct tzhead * tzhp;
 267   char buf[sizeof *sp + sizeof *tzhp];
 268   int ttisstdcnt;
 269
 270   if (name == NULL && (name = TZDEFAULT) == NULL)
 271     return -1;
 272
 273   if (name[0] == ':')
 274     ++name;
 275   if (name[0] != '/')
 276   {
 277     if ((p = tzdir()) == NULL)
 278       return -1;
 279     if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
 280       return -1;
 281     strcpy(fullname, p);
 282     strcat(fullname, "/");
 283     strcat(fullname, name);
 284     name = fullname;
 285   }
 286
 287   if ((fid = _open(name, OPEN_MODE)) == -1)
 288   {
 289     const char *base = strrchr(name, '/');
 290     if (base)
 291       base++;
 292     else
 293       base = name;
 294     if (strcmp(base, "posixrules"))
 295       return -1;
 296
 297     /* We've got a built-in copy of posixrules just in case */
 298     memcpy(buf, _posixrules_data, sizeof(_posixrules_data));
 299     i = sizeof(_posixrules_data);
 300   }
 301   else
 302   {
 303     i = _read(fid, buf, sizeof buf);
 304     if (_close(fid) != 0 || i < (int)sizeof *tzhp)
 305       return -1;
 306   }
 307
 308   tzhp = (struct tzhead *) buf;
 309   ttisstdcnt = (int) detzcode(tzhp->tzh_ttisstdcnt);
 310   sp->leapcnt = (int) detzcode(tzhp->tzh_leapcnt);
 311   sp->timecnt = (int) detzcode(tzhp->tzh_timecnt);
 312   sp->typecnt = (int) detzcode(tzhp->tzh_typecnt);
 313   sp->charcnt = (int) detzcode(tzhp->tzh_charcnt);
 314   if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
 315       sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
 316       sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
 317       sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
 318       (ttisstdcnt != sp->typecnt && ttisstdcnt != 0))
 319     return -1;
 320   if (i < (int)sizeof *tzhp +
 321       sp->timecnt * (4 + (int)sizeof (char)) +
 322       sp->typecnt * (4 + 2 * (int)sizeof (char)) +
 323       sp->charcnt * (int)sizeof (char) +
 324       sp->leapcnt * 2 * 4 +
 325       ttisstdcnt * (int)sizeof (char))
 326     return -1;
 327   p = buf + sizeof *tzhp;
 328   for (i = 0; i < sp->timecnt; ++i)
 329   {
 330     sp->ats[i] = detzcode(p);
 331     p += 4;
 332   }
 333   for (i = 0; i < sp->timecnt; ++i)
 334   {
 335     sp->types[i] = (unsigned char) *p++;
 336     if (sp->types[i] >= sp->typecnt)
 337       return -1;
 338   }
 339   for (i = 0; i < sp->typecnt; ++i)
 340   {
 341     struct ttinfo * ttisp;
 342
 343     ttisp = &sp->ttis[i];
 344     ttisp->tt_gmtoff = detzcode(p);
 345     p += 4;
 346     ttisp->tt_isdst = (unsigned char) *p++;
 347     if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
 348       return -1;
 349     ttisp->tt_abbrind = (unsigned char) *p++;
 350     if (ttisp->tt_abbrind < 0 ||
 351     ttisp->tt_abbrind > sp->charcnt)
 352       return -1;
 353   }
 354   for (i = 0; i < sp->charcnt; ++i)
 355     sp->chars[i] = *p++;
 356   sp->chars[i] = '\0';      /* ensure '\0' at end */
 357   for (i = 0; i < sp->leapcnt; ++i)
 358   {
 359     struct lsinfo * lsisp;
 360
 361     lsisp = &sp->lsis[i];
 362     lsisp->ls_trans = detzcode(p);
 363     p += 4;
 364     lsisp->ls_corr = detzcode(p);
 365     p += 4;
 366   }
 367   for (i = 0; i < sp->typecnt; ++i)
 368   {
 369     struct ttinfo * ttisp;
 370
 371     ttisp = &sp->ttis[i];
 372     if (ttisstdcnt == 0)
 373       ttisp->tt_ttisstd = FALSE;
 374     else
 375     {
 376       ttisp->tt_ttisstd = *p++;
 377       if (ttisp->tt_ttisstd != TRUE &&
 378       ttisp->tt_ttisstd != FALSE)
 379     return -1;
 380     }
 381   }
 382   return 0;
 383 }
 384
 385 static const int mon_lengths[2][MONSPERYEAR] = {
 386 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
 387 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 388 };
 389
 390 static const int year_lengths[2] = {
 391 DAYSPERNYEAR, DAYSPERLYEAR
 392 };
 393
 394 /*
 395 ** Given a pointer into a time zone string, scan until a character that is not
 396 ** a valid character in a zone name is found.  Return a pointer to that
 397 ** character.
 398 */
 399
 400 static const char*
 401 getzname(const char* strp)
 402 {
 403   char c;
 404
 405   while ((c = *strp) != '\0' && !isdigit(c) && c != ',' && c != '-' &&
 406      c != '+')
 407     ++strp;
 408   return strp;
 409 }
 410
 411 /*
 412 ** Given a pointer into a time zone string, extract a number from that string.
 413 ** Check that the number is within a specified range; if it is not, return
 414 ** NULL.
 415 ** Otherwise, return a pointer to the first character not part of the number.
 416 */
 417
 418 static const char*
 419 getnum(const char* strp, int* CPP_CONST nump, const int min, const int max)
 420 {
 421   char c;
 422   int num;
 423
 424   if (strp == NULL || !isdigit(*strp))
 425     return NULL;
 426   num = 0;
 427   while ((c = *strp) != '\0' && isdigit(c))
 428   {
 429     num = num * 10 + (c - '0');
 430     if (num > max)
 431       return NULL;
 432     ++strp;
 433   }
 434   if (num < min)
 435     return NULL;
 436   *nump = num;
 437   return strp;
 438 }
 439
 440 /*
 441 ** Given a pointer into a time zone string, extract a number of seconds,
 442 ** in hh[:mm[:ss]] form, from the string.
 443 ** If any error occurs, return NULL.
 444 ** Otherwise, return a pointer to the first character not part of the number
 445 ** of seconds.
 446 */
 447
 448 static const char *
 449 getsecs(const char *strp, long * CPP_CONST secsp)
 450 {
 451   int num;
 452
 453   strp = getnum(strp, &num, 0, HOURSPERDAY);
 454   if (strp == NULL)
 455     return NULL;
 456   *secsp = num * SECSPERHOUR;
 457   if (*strp == ':')
 458   {
 459     ++strp;
 460     strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
 461     if (strp == NULL)
 462       return NULL;
 463     *secsp += num * SECSPERMIN;
 464     if (*strp == ':')
 465     {
 466       ++strp;
 467       strp = getnum(strp, &num, 0, SECSPERMIN - 1);
 468       if (strp == NULL)
 469     return NULL;
 470       *secsp += num;
 471     }
 472   }
 473   return strp;
 474 }
 475
 476 /*
 477 ** Given a pointer into a time zone string, extract an offset, in
 478 ** [+-]hh[:mm[:ss]] form, from the string.
 479 ** If any error occurs, return NULL.
 480 ** Otherwise, return a pointer to the first character not part of the time.
 481 */
 482
 483 static const char *
 484 getoffset(const char *strp, long * CPP_CONST offsetp)
 485 {
 486   int neg;
 487
 488   if (*strp == '-')
 489   {
 490     neg = 1;
 491     ++strp;
 492   }
 493   else if (isdigit(*strp) || *strp++ == '+')
 494     neg = 0;
 495   else
 496     return NULL; /* illegal offset */
 497   strp = getsecs(strp, offsetp);
 498   if (strp == NULL)
 499     return NULL; /* illegal time */
 500   if (neg)
 501     *offsetp = -*offsetp;
 502   return strp;
 503 }
 504
 505 /*
 506 ** Given a pointer into a time zone string, extract a rule in the form
 507 ** date[/time].  See POSIX section 8 for the format of "date" and "time".
 508 ** If a valid rule is not found, return NULL.
 509 ** Otherwise, return a pointer to the first character not part of the rule.
 510 */
 511
 512 static const char *
 513 getrule(const char *strp, struct rule * CPP_CONST rulep)
 514 {
 515   if (*strp == 'J')
 516   {
 517     /*
 518      ** Julian day.
 519      */
 520     rulep->r_type = JULIAN_DAY;
 521     ++strp;
 522     strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
 523   }
 524   else if (*strp == 'M')
 525   {
 526     /*
 527      ** Month, week, day.
 528      */
 529     rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
 530     ++strp;
 531     strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
 532     if (strp == NULL)
 533       return NULL;
 534     if (*strp++ != '.')
 535       return NULL;
 536     strp = getnum(strp, &rulep->r_week, 1, 5);
 537     if (strp == NULL)
 538       return NULL;
 539     if (*strp++ != '.')
 540       return NULL;
 541     strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
 542   }
 543   else if (isdigit(*strp))
 544   {
 545     /*
 546      ** Day of year.
 547      */
 548     rulep->r_type = DAY_OF_YEAR;
 549     strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
 550   }
 551   else
 552     return NULL;        /* invalid format */
 553   if (strp == NULL)
 554     return NULL;
 555   if (*strp == '/')
 556   {
 557     /*
 558      ** Time specified.
 559      */
 560     ++strp;
 561     strp = getsecs(strp, &rulep->r_time);
 562   }
 563   else
 564     rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
 565   return strp;
 566 }
 567
 568 /*
 569 ** Given the Epoch-relative time of January 1, 00:00:00 GMT, in a year, the
 570 ** year, a rule, and the offset from GMT at the time that rule takes effect,
 571 ** calculate the Epoch-relative time that rule takes effect.
 572 */
 573
 574 static time_t
 575 transtime(const time_t janfirst, const int year, const struct rule * CPP_CONST rulep, const long offset)
 576 {
 577   int leapyear;
 578   time_t value=0;
 579   int i;
 580   int d, m1, yy0, yy1, yy2, dow;
 581
 582   leapyear = isleap(year);
 583   switch (rulep->r_type)
 584   {
 585
 586   case JULIAN_DAY:
 587     /*
 588      ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
 589      ** years.
 590      ** In non-leap years, or if the day number is 59 or less, just
 591      ** add SECSPERDAY times the day number-1 to the time of
 592      ** January 1, midnight, to get the day.
 593      */
 594     value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
 595     if (leapyear && rulep->r_day >= 60)
 596       value += SECSPERDAY;
 597     break;
 598
 599   case DAY_OF_YEAR:
 600     /*
 601      ** n - day of year.
 602      ** Just add SECSPERDAY times the day number to the time of
 603      ** January 1, midnight, to get the day.
 604      */
 605     value = janfirst + rulep->r_day * SECSPERDAY;
 606     break;
 607
 608   case MONTH_NTH_DAY_OF_WEEK:
 609     /*
 610      ** Mm.n.d - nth "dth day" of month m.
 611      */
 612     value = janfirst;
 613     for (i = 0; i < rulep->r_mon - 1; ++i)
 614       value += mon_lengths[leapyear][i] * SECSPERDAY;
 615
 616     /*
 617      ** Use Zeller's Congruence to get day-of-week of first day of
 618      ** month.
 619      */
 620     m1 = (rulep->r_mon + 9) % 12 + 1;
 621     yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
 622     yy1 = yy0 / 100;
 623     yy2 = yy0 % 100;
 624     dow = ((26 * m1 - 2) / 10 +
 625        1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
 626     if (dow < 0)
 627       dow += DAYSPERWEEK;
 628
 629     /*
 630      ** "dow" is the day-of-week of the first day of the month.  Get
 631      ** the day-of-month (zero-origin) of the first "dow" day of the
 632      ** month.
 633      */
 634     d = rulep->r_day - dow;
 635     if (d < 0)
 636       d += DAYSPERWEEK;
 637     for (i = 1; i < rulep->r_week; ++i)
 638     {
 639       if (d + DAYSPERWEEK >=
 640       mon_lengths[leapyear][rulep->r_mon - 1])
 641     break;
 642       d += DAYSPERWEEK;
 643     }
 644
 645     /*
 646      ** "d" is the day-of-month (zero-origin) of the day we want.
 647      */
 648     value += d * SECSPERDAY;
 649     break;
 650   }
 651
 652   /*
 653    ** "value" is the Epoch-relative time of 00:00:00 GMT on the day in
 654    ** question.  To get the Epoch-relative time of the specified local
 655    ** time on that day, add the transition time and the current offset
 656    ** from GMT.
 657    */
 658   return value + rulep->r_time + offset;
 659 }
 660
 661 /*
 662 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
 663 ** appropriate.
 664 */
 665
 666 static int
 667 tzparse(const char *name, struct state * CPP_CONST sp, const int lastditch)
 668 {
 669   const char * stdname;
 670   const char * dstname=0;
 671   int stdlen;
 672   int dstlen;
 673   long stdoffset;
 674   long dstoffset;
 675   time_t * atp;
 676   unsigned char * typep;
 677   char * cp;
 678   int load_result;
 679
 680   stdname = name;
 681   if (lastditch)
 682   {
 683     stdlen = strlen(name);  /* length of standard zone name */
 684     name += stdlen;
 685     if (stdlen >= (int)sizeof sp->chars)
 686       stdlen = (int)(sizeof sp->chars) - 1;
 687   }
 688   else
 689   {
 690     name = getzname(name);
 691     stdlen = name - stdname;
 692     if (stdlen < 3)
 693       return -1;
 694   }
 695   if (*name == '\0')
 696     return -1;
 697   else
 698   {
 699     name = getoffset(name, &stdoffset);
 700     if (name == NULL)
 701       return -1;
 702   }
 703   load_result = tzload(TZDEFRULES, sp);
 704   if (load_result != 0)
 705     sp->leapcnt = 0;        /* so, we're off a little */
 706   if (*name != '\0')
 707   {
 708     dstname = name;
 709     name = getzname(name);
 710     dstlen = name - dstname;    /* length of DST zone name */
 711     if (dstlen < 3)
 712       return -1;
 713     if (*name != '\0' && *name != ',' && *name != ';')
 714     {
 715       name = getoffset(name, &dstoffset);
 716       if (name == NULL)
 717     return -1;
 718     }
 719     else
 720       dstoffset = stdoffset - SECSPERHOUR;
 721     if (*name == ',' || *name == ';')
 722     {
 723       struct rule start;
 724       struct rule end;
 725       int year;
 726       time_t janfirst;
 727       time_t starttime;
 728       time_t endtime;
 729
 730       ++name;
 731       if ((name = getrule(name, &start)) == NULL)
 732     return -1;
 733       if (*name++ != ',')
 734     return -1;
 735       if ((name = getrule(name, &end)) == NULL)
 736     return -1;
 737       if (*name != '\0')
 738     return -1;
 739       sp->typecnt = 2;      /* standard time and DST */
 740       /*
 741        ** Two transitions per year, from EPOCH_YEAR to 2037.
 742        */
 743       sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
 744       if (sp->timecnt > TZ_MAX_TIMES)
 745     return -1;
 746       sp->ttis[0].tt_gmtoff = -dstoffset;
 747       sp->ttis[0].tt_isdst = 1;
 748       sp->ttis[0].tt_abbrind = stdlen + 1;
 749       sp->ttis[1].tt_gmtoff = -stdoffset;
 750       sp->ttis[1].tt_isdst = 0;
 751       sp->ttis[1].tt_abbrind = 0;
 752       atp = sp->ats;
 753       typep = sp->types;
 754       janfirst = 0;
 755       for (year = EPOCH_YEAR; year <= 2037; ++year)
 756       {
 757     starttime = transtime(janfirst, year, &start,
 758                   stdoffset);
 759     endtime = transtime(janfirst, year, &end,
 760                 dstoffset);
 761     if (starttime > endtime)
 762     {
 763       *atp++ = endtime;
 764       *typep++ = 1;     /* DST ends */
 765       *atp++ = starttime;
 766       *typep++ = 0;     /* DST begins */
 767     }
 768     else
 769     {
 770       *atp++ = starttime;
 771       *typep++ = 0;     /* DST begins */
 772       *atp++ = endtime;
 773       *typep++ = 1;     /* DST ends */
 774     }
 775     janfirst +=
 776       year_lengths[isleap(year)] * SECSPERDAY;
 777       }
 778     }
 779     else
 780     {
 781       int sawstd;
 782       int sawdst;
 783       long stdfix;
 784       long dstfix;
 785       long oldfix;
 786       int isdst;
 787       int i;
 788
 789       if (*name != '\0')
 790     return -1;
 791       if (load_result != 0)
 792     return -1;
 793       /*
 794        ** Compute the difference between the real and
 795        ** prototype standard and summer time offsets
 796        ** from GMT, and put the real standard and summer
 797        ** time offsets into the rules in place of the
 798        ** prototype offsets.
 799        */
 800       sawstd = FALSE;
 801       sawdst = FALSE;
 802       stdfix = 0;
 803       dstfix = 0;
 804       for (i = 0; i < sp->typecnt; ++i)
 805       {
 806     if (sp->ttis[i].tt_isdst)
 807     {
 808       oldfix = dstfix;
 809       dstfix =
 810         sp->ttis[i].tt_gmtoff + dstoffset;
 811       if (sawdst && (oldfix != dstfix))
 812         return -1;
 813       sp->ttis[i].tt_gmtoff = -dstoffset;
 814       sp->ttis[i].tt_abbrind = stdlen + 1;
 815       sawdst = TRUE;
 816     }
 817     else
 818     {
 819       oldfix = stdfix;
 820       stdfix =
 821         sp->ttis[i].tt_gmtoff + stdoffset;
 822       if (sawstd && (oldfix != stdfix))
 823         return -1;
 824       sp->ttis[i].tt_gmtoff = -stdoffset;
 825       sp->ttis[i].tt_abbrind = 0;
 826       sawstd = TRUE;
 827     }
 828       }
 829       /*
 830        ** Make sure we have both standard and summer time.
 831        */
 832       if (!sawdst || !sawstd)
 833     return -1;
 834       /*
 835        ** Now correct the transition times by shifting
 836        ** them by the difference between the real and
 837        ** prototype offsets.  Note that this difference
 838        ** can be different in standard and summer time;
 839        ** the prototype probably has a 1-hour difference
 840        ** between standard and summer time, but a different
 841        ** difference can be specified in TZ.
 842        */
 843       isdst = FALSE; /* we start in standard time */
 844       for (i = 0; i < sp->timecnt; ++i)
 845       {
 846     const struct ttinfo * ttisp;
 847
 848     /*
 849      ** If summer time is in effect, and the
 850      ** transition time was not specified as
 851      ** standard time, add the summer time
 852      ** offset to the transition time;
 853      ** otherwise, add the standard time offset
 854      ** to the transition time.
 855      */
 856     ttisp = &sp->ttis[sp->types[i]];
 857     sp->ats[i] +=
 858       (isdst && !ttisp->tt_ttisstd) ?
 859         dstfix : stdfix;
 860     isdst = ttisp->tt_isdst;
 861       }
 862     }
 863   }
 864   else
 865   {
 866     dstlen = 0;
 867     sp->typecnt = 1;        /* only standard time */
 868     sp->timecnt = 0;
 869     sp->ttis[0].tt_gmtoff = -stdoffset;
 870     sp->ttis[0].tt_isdst = 0;
 871     sp->ttis[0].tt_abbrind = 0;
 872   }
 873   sp->charcnt = stdlen + 1;
 874   if (dstlen != 0)
 875     sp->charcnt += dstlen + 1;
 876   if (sp->charcnt > (int)sizeof sp->chars)
 877     return -1;
 878   cp = sp->chars;
 879   (void) strncpy(cp, stdname, stdlen);
 880   cp += stdlen;
 881   *cp++ = '\0';
 882   if (dstlen != 0)
 883   {
 884     (void) strncpy(cp, dstname, dstlen);
 885     *(cp + dstlen) = '\0';
 886   }
 887   return 0;
 888 }
 889
 890 static void
 891 gmtload(struct state * CPP_CONST sp)
 892 {
 893   if (tzload(GMT, sp) != 0)
 894     (void) tzparse(GMT, sp, TRUE);
 895 }
 896
 897 /*
 898  * @implemented
 899  */
 900 void
 901 _tzset(void)
 902 {
 903   const char * name;
 904
 905   name = getenv("TZ");
 906   if (name == NULL)
 907   {
 908     tzsetwall();
 909     return;
 910   }
 911   lcl_is_set = TRUE;
 912 #ifdef ALL_STATE
 913   if (lclptr == NULL)
 914   {
 915     lclptr = (struct state *) malloc(sizeof *lclptr);
 916     if (lclptr == NULL)
 917     {
 918       settzname();      /* all we can do */
 919       return;
 920     }
 921   }
 922 #endif /* defined ALL_STATE */
 923   if (*name == '\0')
 924   {
 925     /*
 926      ** User wants it fast rather than right.
 927      */
 928     lclptr->leapcnt = 0;    /* so, we're off a little */
 929     lclptr->timecnt = 0;
 930     lclptr->ttis[0].tt_gmtoff = 0;
 931     lclptr->ttis[0].tt_abbrind = 0;
 932     (void) strcpy(lclptr->chars, GMT);
 933   }
 934   else if (tzload(name, lclptr) != 0)
 935     if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
 936       gmtload(lclptr);
 937   settzname();
 938 }
 939
 940 void
 941 tzsetwall(void)
 942 {
 943   lcl_is_set = TRUE;
 944 #ifdef ALL_STATE
 945   if (lclptr == NULL)
 946   {
 947     lclptr = (struct state *) malloc(sizeof *lclptr);
 948     if (lclptr == NULL)
 949     {
 950       settzname();      /* all we can do */
 951       return;
 952     }
 953   }
 954 #endif /* defined ALL_STATE */
 955   if (tzload((char *) NULL, lclptr) != 0)
 956     gmtload(lclptr);
 957   settzname();
 958 }
 959
 960 /*
 961 ** The easy way to behave "as if no library function calls" localtime
 962 ** is to not call it--so we drop its guts into "localsub", which can be
 963 ** freely called.  (And no, the PANS doesn't require the above behavior--
 964 ** but it *is* desirable.)
 965 **
 966 ** The unused offset argument is for the benefit of mktime variants.
 967 */
 968
 969 /*ARGSUSED*/
 970 static void
 971 localsub(const time_t * CPP_CONST timep, const long offset, struct tm * CPP_CONST tmp)
 972 {
 973   const struct state * sp;
 974   const struct ttinfo * ttisp;
 975   int i;
 976   const time_t t = *timep;
 977
 978   if (!lcl_is_set)
 979     _tzset();
 980   sp = lclptr;
 981 #ifdef ALL_STATE
 982   if (sp == NULL)
 983   {
 984     gmtsub(timep, offset, tmp);
 985     return;
 986   }
 987 #endif /* defined ALL_STATE */
 988   if (sp->timecnt == 0 || t < sp->ats[0])
 989   {
 990     i = 0;
 991     while (sp->ttis[i].tt_isdst)
 992       if (++i >= sp->typecnt)
 993       {
 994     i = 0;
 995     break;
 996       }
 997   }
 998   else
 999   {
1000     for (i = 1; i < sp->timecnt; ++i)
1001       if (t < sp->ats[i])
1002     break;
1003     i = sp->types[i - 1];
1004   }
1005   ttisp = &sp->ttis[i];
1006   /*
1007    ** To get (wrong) behavior that's compatible with System V Release 2.0
1008    ** you'd replace the statement below with
1009    ** t += ttisp->tt_gmtoff;
1010    ** timesub(&t, 0L, sp, tmp);
1011    */
1012   timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1013   tmp->tm_isdst = ttisp->tt_isdst;
1014   _tzname[tmp->tm_isdst] = (char *)&sp->chars[ttisp->tt_abbrind];
1015 #if 0
1016 /* tm_zone doesnt exist in windows msvcrt -Gunnar */
1017   tmp->tm_zone = (char *)&sp->chars[ttisp->tt_abbrind];
1018 #endif
1019 }
1020
1021 /*
1022  * @implemented
1023  */
1024 struct tm *
1025 localtime(const time_t * CPP_CONST timep)
1026 {
1027   static struct tm tm;
1028
1029   localsub(timep, 0L, &tm);
1030   return &tm;
1031 }
1032
1033 /*
1034 ** gmtsub is to gmtime as localsub is to localtime.
1035 */
1036
1037 static void
1038 gmtsub(const time_t * CPP_CONST timep, const long offset, struct tm * CPP_CONST tmp)
1039 {
1040   if (!gmt_is_set)
1041   {
1042     gmt_is_set = TRUE;
1043 #ifdef ALL_STATE
1044     gmtptr = (struct state *) malloc(sizeof *gmtptr);
1045     if (gmtptr != NULL)
1046 #endif /* defined ALL_STATE */
1047       gmtload(gmtptr);
1048   }
1049   timesub(timep, offset, gmtptr, tmp);
1050   /*
1051    ** Could get fancy here and deliver something such as
1052    ** "GMT+xxxx" or "GMT-xxxx" if offset is non-zero,
1053    ** but this is no time for a treasure hunt.
1054    */
1055 #if 0
1056 /* tm_zone doesnt exist in windows msvcrt -Gunnar */
1057   if (offset != 0)
1058     tmp->tm_zone = TZ_NAME;
1059   else
1060   {
1061 #ifdef ALL_STATE
1062     if (gmtptr == NULL)
1063       tmp->TM_ZONE = GMT;
1064     else
1065       tmp->TM_ZONE = gmtptr->chars;
1066 #endif /* defined ALL_STATE */
1067 #ifndef ALL_STATE
1068     tmp->tm_zone = gmtptr->chars;
1069 #endif /* State Farm */
1070   }
1071 #endif /* if 0 */
1072 }
1073
1074 /*
1075  * @implemented
1076  */
1077 struct tm *
1078 gmtime(const time_t * CPP_CONST timep)
1079 {
1080   static struct tm tm;
1081
1082   gmtsub(timep, 0L, &tm);
1083   return &tm;
1084 }
1085
1086 static void
1087 timesub(const time_t * CPP_CONST timep, const long offset, const struct state * CPP_CONST sp, struct tm * CPP_CONST tmp)
1088 {
1089   const struct lsinfo * lp;
1090   long days;
1091   long rem;
1092   int y;
1093   int yleap;
1094   const int * ip;
1095   long corr;
1096   int hit;
1097   int i;
1098
1099   corr = 0;
1100   hit = FALSE;
1101 #ifdef ALL_STATE
1102   i = (sp == NULL) ? 0 : sp->leapcnt;
1103 #endif /* defined ALL_STATE */
1104 #ifndef ALL_STATE
1105   i = sp->leapcnt;
1106 #endif /* State Farm */
1107   while (--i >= 0)
1108   {
1109     lp = &sp->lsis[i];
1110     if (*timep >= lp->ls_trans)
1111     {
1112       if (*timep == lp->ls_trans)
1113     hit = ((i == 0 && lp->ls_corr > 0) ||
1114            lp->ls_corr > sp->lsis[i - 1].ls_corr);
1115       corr = lp->ls_corr;
1116       break;
1117     }
1118   }
1119   days = *timep / SECSPERDAY;
1120   rem = *timep % SECSPERDAY;
1121 #ifdef mc68k
1122   if (*timep == 0x80000000)
1123   {
1124     /*
1125      ** A 3B1 muffs the division on the most negative number.
1126      */
1127     days = -24855;
1128     rem = -11648;
1129   }
1130 #endif /* mc68k */
1131   rem += (offset - corr);
1132   while (rem < 0)
1133   {
1134     rem += SECSPERDAY;
1135     --days;
1136   }
1137   while (rem >= SECSPERDAY)
1138   {
1139     rem -= SECSPERDAY;
1140     ++days;
1141   }
1142   tmp->tm_hour = (int) (rem / SECSPERHOUR);
1143   rem = rem % SECSPERHOUR;
1144   tmp->tm_min = (int) (rem / SECSPERMIN);
1145   tmp->tm_sec = (int) (rem % SECSPERMIN);
1146   if (hit)
1147     /*
1148      ** A positive leap second requires a special
1149      ** representation.  This uses "... ??:59:60".
1150      */
1151     ++(tmp->tm_sec);
1152   tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
1153   if (tmp->tm_wday < 0)
1154     tmp->tm_wday += DAYSPERWEEK;
1155   y = EPOCH_YEAR;
1156   if (days >= 0)
1157     for ( ; ; )
1158     {
1159       yleap = isleap(y);
1160       if (days < (long) year_lengths[yleap])
1161     break;
1162       ++y;
1163       days = days - (long) year_lengths[yleap];
1164     }
1165   else
1166     do {
1167     --y;
1168     yleap = isleap(y);
1169     days = days + (long) year_lengths[yleap];
1170   } while (days < 0);
1171   tmp->tm_year = y - TM_YEAR_BASE;
1172   tmp->tm_yday = (int) days;
1173   ip = mon_lengths[yleap];
1174   for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
1175     days = days - (long) ip[tmp->tm_mon];
1176   tmp->tm_mday = (int) (days + 1);
1177   tmp->tm_isdst = 0;
1178 #if 0
1179 /* tm_gmtoff doesnt exist in windows msvcrt -Gunnar */
1180   tmp->tm_gmtoff = offset;
1181 #endif
1182 }
1183
1184 /*
1185 ** A la X3J11
1186 */
1187
1188 /*
1189  * @implemented
1190  */
1191 char *
1192 asctime(const struct tm *timeptr)
1193 {
1194   static const char wday_name[DAYSPERWEEK][3] = {
1195     "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
1196   };
1197   static const char mon_name[MONSPERYEAR][3] = {
1198     "Jan", "Feb", "Mar", "Apr", "May", "Jun",
1199     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
1200   };
1201   static char result[26];
1202
1203   (void) sprintf(result, "%.3s %.3s%3d %02d:%02d:%02d %d\n",
1204          wday_name[timeptr->tm_wday],
1205          mon_name[timeptr->tm_mon],
1206          timeptr->tm_mday, timeptr->tm_hour,
1207          timeptr->tm_min, timeptr->tm_sec,
1208          TM_YEAR_BASE + timeptr->tm_year);
1209   return result;
1210 }
1211
1212 /*
1213  * @implemented
1214  */
1215 char *
1216 ctime(const time_t * CPP_CONST timep)
1217 {
1218   return asctime(localtime(timep));
1219 }
1220
1221 /*
1222 ** Adapted from code provided by Robert Elz, who writes:
1223 **  The "best" way to do mktime I think is based on an idea of Bob
1224 **  Kridle's (so its said...) from a long time ago. (mtxinu!kridle now).
1225 **  It does a binary search of the time_t space.  Since time_t's are
1226 **  just 32 bits, its a max of 32 iterations (even at 64 bits it
1227 **  would still be very reasonable).
1228 */
1229
1230 #ifndef WRONG
1231 #define WRONG   (-1)
1232 #endif /* !defined WRONG */
1233
1234 static void
1235 normalize(int * CPP_CONST tensptr, int * CPP_CONST unitsptr, const int base)
1236 {
1237   if (*unitsptr >= base)
1238   {
1239     *tensptr += *unitsptr / base;
1240     *unitsptr %= base;
1241   }
1242   else if (*unitsptr < 0)
1243   {
1244     --*tensptr;
1245     *unitsptr += base;
1246     if (*unitsptr < 0)
1247     {
1248       *tensptr -= 1 + (-*unitsptr) / base;
1249       *unitsptr = base - (-*unitsptr) % base;
1250     }
1251   }
1252 }
1253
1254 static int
1255 tmcomp(const struct tm * CPP_CONST atmp, const struct tm * CPP_CONST btmp)
1256 {
1257   int result;
1258
1259   if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1260       (result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1261       (result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1262       (result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1263       (result = (atmp->tm_min - btmp->tm_min)) == 0)
1264     result = atmp->tm_sec - btmp->tm_sec;
1265   return result;
1266 }
1267
1268 static time_t
1269 time2(struct tm *tmp, void (*const funcp)(const time_t * CPP_CONST, const long, struct tm *), const long offset, int * CPP_CONST okayp)
1270 {
1271   const struct state * sp;
1272   int dir;
1273   int bits;
1274   int i, j ;
1275   int saved_seconds;
1276   time_t newt;
1277   time_t t;
1278   struct tm yourtm, mytm;
1279
1280   *okayp = FALSE;
1281   yourtm = *tmp;
1282   if (yourtm.tm_sec >= SECSPERMIN + 2 || yourtm.tm_sec < 0)
1283     normalize(&yourtm.tm_min, &yourtm.tm_sec, SECSPERMIN);
1284   normalize(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR);
1285   normalize(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY);
1286   normalize(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR);
1287   while (yourtm.tm_mday <= 0)
1288   {
1289     --yourtm.tm_year;
1290     yourtm.tm_mday +=
1291       year_lengths[isleap(yourtm.tm_year + TM_YEAR_BASE)];
1292   }
1293   for ( ; ; )
1294   {
1295     i = mon_lengths[isleap(yourtm.tm_year +
1296                TM_YEAR_BASE)][yourtm.tm_mon];
1297     if (yourtm.tm_mday <= i)
1298       break;
1299     yourtm.tm_mday -= i;
1300     if (++yourtm.tm_mon >= MONSPERYEAR)
1301     {
1302       yourtm.tm_mon = 0;
1303       ++yourtm.tm_year;
1304     }
1305   }
1306   saved_seconds = yourtm.tm_sec;
1307   yourtm.tm_sec = 0;
1308   /*
1309    ** Calculate the number of magnitude bits in a time_t
1310    ** (this works regardless of whether time_t is
1311    ** signed or unsigned, though lint complains if unsigned).
1312    */
1313   for (bits = 0, t = 1; t > 0; ++bits, t <<= 1)
1314     ;
1315   /*
1316    ** If time_t is signed, then 0 is the median value,
1317    ** if time_t is unsigned, then 1 << bits is median.
1318    */
1319 #ifdef _MSVCRT_LIB_
1320   t = (time_t) ((1 << bits) - 1);
1321 #else // TODO: FIXME: review which is correct
1322   t = (time_t) 1 << bits;
1323 #endif /*_MSVCRT_LIB_*/
1324
1325   for ( ; ; )
1326   {
1327     (*funcp)(&t, offset, &mytm);
1328     dir = tmcomp(&mytm, &yourtm);
1329     if (dir != 0)
1330     {
1331       if (bits-- < 0)
1332     return WRONG;
1333       if (bits < 0)
1334     --t;
1335       else if (dir > 0)
1336     t -= (time_t) 1 << bits;
1337       else t += (time_t) 1 << bits;
1338       continue;
1339     }
1340     if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1341       break;
1342     /*
1343      ** Right time, wrong type.
1344      ** Hunt for right time, right type.
1345      ** It's okay to guess wrong since the guess
1346      ** gets checked.
1347      */
1348     sp = (const struct state *)
1349       ((funcp == localsub) ? lclptr : gmtptr);
1350 #ifdef ALL_STATE
1351     if (sp == NULL)
1352       return WRONG;
1353 #endif /* defined ALL_STATE */
1354     for (i = 0; i < sp->typecnt; ++i)
1355     {
1356       if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1357     continue;
1358       for (j = 0; j < sp->typecnt; ++j)
1359       {
1360     if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1361       continue;
1362     newt = t + sp->ttis[j].tt_gmtoff -
1363       sp->ttis[i].tt_gmtoff;
1364     (*funcp)(&newt, offset, &mytm);
1365     if (tmcomp(&mytm, &yourtm) != 0)
1366       continue;
1367     if (mytm.tm_isdst != yourtm.tm_isdst)
1368       continue;
1369     /*
1370      ** We have a match.
1371      */
1372     t = newt;
1373     goto label;
1374       }
1375     }
1376     return WRONG;
1377   }
1378  label:
1379   t += saved_seconds;
1380   (*funcp)(&t, offset, tmp);
1381   *okayp = TRUE;
1382   return t;
1383 }
1384
1385 static time_t
1386 time1(struct tm * CPP_CONST tmp, void (*const funcp)(const time_t * CPP_CONST, const long, struct tm *), const long offset)
1387 {
1388   time_t t;
1389   const struct state * sp;
1390   int samei, otheri;
1391   int okay;
1392
1393   if (tmp->tm_isdst > 1)
1394     tmp->tm_isdst = 1;
1395   t = time2(tmp, funcp, offset, &okay);
1396   if (okay || tmp->tm_isdst < 0)
1397     return t;
1398   /*
1399    ** We're supposed to assume that somebody took a time of one type
1400    ** and did some math on it that yielded a "struct tm" that's bad.
1401    ** We try to divine the type they started from and adjust to the
1402    ** type they need.
1403    */
1404   sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr);
1405 #ifdef ALL_STATE
1406   if (sp == NULL)
1407     return WRONG;
1408 #endif /* defined ALL_STATE */
1409   for (samei = 0; samei < sp->typecnt; ++samei)
1410   {
1411     if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
1412       continue;
1413     for (otheri = 0; otheri < sp->typecnt; ++otheri)
1414     {
1415       if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
1416     continue;
1417       tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
1418     sp->ttis[samei].tt_gmtoff;
1419       tmp->tm_isdst = !tmp->tm_isdst;
1420       t = time2(tmp, funcp, offset, &okay);
1421       if (okay)
1422     return t;
1423       tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
1424     sp->ttis[samei].tt_gmtoff;
1425       tmp->tm_isdst = !tmp->tm_isdst;
1426     }
1427   }
1428   return WRONG;
1429 }
1430
1431 /*
1432  * @implemented
1433  */
1434 time_t
1435 mktime(struct tm * tmp)
1436 {
1437   return time1(tmp, localsub, 0L);
1438 }