time/strptime_l.c

   1 /* Copyright (C) 2002-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #include <assert.h>
  23 #include <ctype.h>
  24 #include <langinfo.h>
  25 #include <limits.h>
  26 #include <string.h>
  27 #include <time.h>
  28 #include <stdbool.h>
  29
  30 #ifdef _LIBC
  31 # define HAVE_LOCALTIME_R 0
  32 # include "../locale/localeinfo.h"
  33 #endif
  34
  35
  36 #if ! HAVE_LOCALTIME_R && ! defined localtime_r
  37 # ifdef _LIBC
  38 #  define localtime_r __localtime_r
  39 # else
  40 /* Approximate localtime_r as best we can in its absence.  */
  41 #  define localtime_r my_localtime_r
  42 static struct tm *localtime_r (const time_t *, struct tm *);
  43 static struct tm *
  44 localtime_r (const time_t *t, struct tm *tp)
  45 {
  46   struct tm *l = localtime (t);
  47   if (! l)
  48     return 0;
  49   *tp = *l;
  50   return tp;
  51 }
  52 # endif /* ! _LIBC */
  53 #endif /* ! HAVE_LOCALTIME_R && ! defined (localtime_r) */
  54
  55
  56 #define match_char(ch1, ch2) if (ch1 != ch2) return NULL
  57 #if defined __GNUC__ && __GNUC__ >= 2
  58 # define match_string(cs1, s2) \
  59   ({ size_t len = strlen (cs1);                                               \
  60      int result = __strncasecmp_l ((cs1), (s2), len, locale) == 0;            \
  61      if (result) (s2) += len;                                                 \
  62      result; })
  63 #else
  64 /* Oh come on.  Get a reasonable compiler.  */
  65 # define match_string(cs1, s2) \
  66   (strncasecmp ((cs1), (s2), strlen (cs1)) ? 0 : ((s2) += strlen (cs1), 1))
  67 #endif
  68 /* We intentionally do not use isdigit() for testing because this will
  69    lead to problems with the wide character version.  */
  70 #define get_number(from, to, n) \
  71   do {                                                                        \
  72     int __n = n;                                                              \
  73     val = 0;                                                                  \
  74     while (ISSPACE (*rp))                                                     \
  75       ++rp;                                                                   \
  76     if (*rp < '0' || *rp > '9')                                               \
  77       return NULL;                                                            \
  78     do {                                                                      \
  79       val *= 10;                                                              \
  80       val += *rp++ - '0';                                                     \
  81     } while (--__n > 0 && val * 10 <= to && *rp >= '0' && *rp <= '9');        \
  82     if (val < from || val > to)                                               \
  83       return NULL;                                                            \
  84   } while (0)
  85 #ifdef _NL_CURRENT
  86 # define get_alt_number(from, to, n) \
  87   ({                                                                          \
  88      __label__ do_normal;                                                     \
  89                                                                               \
  90      if (s.decided != raw)                                                    \
  91        {                                                                      \
  92          val = _nl_parse_alt_digit (&rp HELPER_LOCALE_ARG);                   \
  93          if (val == -1 && s.decided != loc)                                   \
  94            {                                                                  \
  95              s.decided = loc;                                                 \
  96              goto do_normal;                                                  \
  97            }                                                                  \
  98         if (val < from || val > to)                                           \
  99           return NULL;                                                        \
 100        }                                                                      \
 101      else                                                                     \
 102        {                                                                      \
 103        do_normal:                                                             \
 104          get_number (from, to, n);                                            \
 105        }                                                                      \
 106     0;                                                                        \
 107   })
 108 #else
 109 # define get_alt_number(from, to, n) \
 110   /* We don't have the alternate representation.  */                          \
 111   get_number(from, to, n)
 112 #endif
 113 #define recursive(new_fmt) \
 114   (*(new_fmt) != '\0'                                                         \
 115    && (rp = __strptime_internal (rp, (new_fmt), tm, &s LOCALE_ARG)) != NULL)
 116
 117
 118 #ifdef _LIBC
 119 /* This is defined in locale/C-time.c in the GNU libc.  */
 120 extern const struct __locale_data _nl_C_LC_TIME attribute_hidden;
 121
 122 # define weekday_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (DAY_1)].string)
 123 # define ab_weekday_name \
 124   (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABDAY_1)].string)
 125 # define month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (MON_1)].string)
 126 # define ab_month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABMON_1)].string)
 127 # define alt_month_name \
 128   (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ALTMON_1)].string)
 129 # define ab_alt_month_name \
 130   (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (_NL_ABALTMON_1)].string)
 131 # define HERE_D_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_T_FMT)].string)
 132 # define HERE_D_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_FMT)].string)
 133 # define HERE_AM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (AM_STR)].string)
 134 # define HERE_PM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (PM_STR)].string)
 135 # define HERE_T_FMT_AMPM \
 136   (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT_AMPM)].string)
 137 # define HERE_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT)].string)
 138
 139 # define strncasecmp(s1, s2, n) __strncasecmp (s1, s2, n)
 140 #else
 141 static char const weekday_name[][10] =
 142   {
 143     "Sunday", "Monday", "Tuesday", "Wednesday",
 144     "Thursday", "Friday", "Saturday"
 145   };
 146 static char const ab_weekday_name[][4] =
 147   {
 148     "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
 149   };
 150 static char const month_name[][10] =
 151   {
 152     "January", "February", "March", "April", "May", "June",
 153     "July", "August", "September", "October", "November", "December"
 154   };
 155 static char const ab_month_name[][4] =
 156   {
 157     "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 158     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 159   };
 160 # define HERE_D_T_FMT "%a %b %e %H:%M:%S %Y"
 161 # define HERE_D_FMT "%m/%d/%y"
 162 # define HERE_AM_STR "AM"
 163 # define HERE_PM_STR "PM"
 164 # define HERE_T_FMT_AMPM "%I:%M:%S %p"
 165 # define HERE_T_FMT "%H:%M:%S"
 166
 167 static const unsigned short int __mon_yday[2][13] =
 168   {
 169     /* Normal years.  */
 170     { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
 171     /* Leap years.  */
 172     { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
 173   };
 174 #endif
 175
 176 #if defined _LIBC
 177 /* We use this code also for the extended locale handling where the
 178    function gets as an additional argument the locale which has to be
 179    used.  To access the values we have to redefine the _NL_CURRENT
 180    macro.  */
 181 # define strptime               __strptime_l
 182 # undef _NL_CURRENT
 183 # define _NL_CURRENT(category, item) \
 184   (current->values[_NL_ITEM_INDEX (item)].string)
 185 # undef _NL_CURRENT_WORD
 186 # define _NL_CURRENT_WORD(category, item) \
 187   (current->values[_NL_ITEM_INDEX (item)].word)
 188 # define LOCALE_PARAM , locale_t locale
 189 # define LOCALE_ARG , locale
 190 # define HELPER_LOCALE_ARG , current
 191 # define ISSPACE(Ch) __isspace_l (Ch, locale)
 192 #else
 193 # define LOCALE_PARAM
 194 # define LOCALE_ARG
 195 # define HELPER_LOCALE_ARG
 196 # define ISSPACE(Ch) isspace (Ch)
 197 #endif
 198
 199
 200
 201
 202 #ifndef __isleap
 203 /* Nonzero if YEAR is a leap year (every 4 years,
 204    except every 100th isn't, and every 400th is).  */
 205 # define __isleap(year) \
 206   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 207 #endif
 208
 209 /* Compute the day of the week.  */
 210 static void
 211 day_of_the_week (struct tm *tm)
 212 {
 213   /* We know that January 1st 1970 was a Thursday (= 4).  Compute the
 214      difference between this data in the one on TM and so determine
 215      the weekday.  */
 216   int corr_year = 1900 + tm->tm_year - (tm->tm_mon < 2);
 217   int wday = (-473
 218               + (365 * (tm->tm_year - 70))
 219               + (corr_year / 4)
 220               - ((corr_year / 4) / 25) + ((corr_year / 4) % 25 < 0)
 221               + (((corr_year / 4) / 25) / 4)
 222               + __mon_yday[0][tm->tm_mon]
 223               + tm->tm_mday - 1);
 224   tm->tm_wday = ((wday % 7) + 7) % 7;
 225 }
 226
 227 /* Compute the day of the year.  */
 228 static void
 229 day_of_the_year (struct tm *tm)
 230 {
 231   tm->tm_yday = (__mon_yday[__isleap (1900 + tm->tm_year)][tm->tm_mon]
 232                  + (tm->tm_mday - 1));
 233 }
 234
 235
 236 #ifdef _LIBC
 237 char *
 238 #else
 239 static char *
 240 #endif
 241 __strptime_internal (const char *rp, const char *fmt, struct tm *tmp,
 242                      void *statep LOCALE_PARAM)
 243 {
 244 #ifdef _LIBC
 245   struct __locale_data *const current = locale->__locales[LC_TIME];
 246 #endif
 247
 248   const char *rp_backup;
 249   const char *rp_longest;
 250   int cnt;
 251   int cnt_longest;
 252   size_t val;
 253   size_t num_eras;
 254   struct era_entry *era = NULL;
 255   enum ptime_locale_status { not, loc, raw } decided_longest;
 256   struct __strptime_state
 257   {
 258     unsigned int have_I : 1;
 259     unsigned int have_wday : 1;
 260     unsigned int have_yday : 1;
 261     unsigned int have_mon : 1;
 262     unsigned int have_mday : 1;
 263     unsigned int have_uweek : 1;
 264     unsigned int have_wweek : 1;
 265     unsigned int is_pm : 1;
 266     unsigned int want_century : 1;
 267     unsigned int want_era : 1;
 268     unsigned int want_xday : 1;
 269     enum ptime_locale_status decided : 2;
 270     signed char week_no;
 271     signed char century;
 272     int era_cnt;
 273   } s;
 274   struct tm tmb;
 275   struct tm *tm;
 276
 277   if (statep == NULL)
 278     {
 279       memset (&s, 0, sizeof (s));
 280       s.century = -1;
 281       s.era_cnt = -1;
 282 #ifdef _NL_CURRENT
 283       s.decided = not;
 284 #else
 285       s.decided = raw;
 286 #endif
 287       tm = tmp;
 288     }
 289   else
 290     {
 291       s = *(struct __strptime_state *) statep;
 292       tmb = *tmp;
 293       tm = &tmb;
 294     }
 295
 296   while (*fmt != '\0')
 297     {
 298       /* A white space in the format string matches 0 more or white
 299          space in the input string.  */
 300       if (ISSPACE (*fmt))
 301         {
 302           while (ISSPACE (*rp))
 303             ++rp;
 304           ++fmt;
 305           continue;
 306         }
 307
 308       /* Any character but `%' must be matched by the same character
 309          in the input string.  */
 310       if (*fmt != '%')
 311         {
 312           match_char (*fmt++, *rp++);
 313           continue;
 314         }
 315
 316       ++fmt;
 317       /* We discard strftime modifiers.  */
 318       while (*fmt == '-' || *fmt == '_' || *fmt == '0'
 319              || *fmt == '^' || *fmt == '#')
 320         ++fmt;
 321
 322       /* And field width.  */
 323       while (*fmt >= '0' && *fmt <= '9')
 324         ++fmt;
 325
 326       /* In some cases, modifiers are handled by adjusting state and
 327          then restarting the switch statement below.  */
 328     start_over:
 329
 330       /* Make back up of current processing pointer.  */
 331       rp_backup = rp;
 332
 333       switch (*fmt++)
 334         {
 335         case '%':
 336           /* Match the `%' character itself.  */
 337           match_char ('%', *rp++);
 338           break;
 339         case 'a':
 340         case 'A':
 341           /* Match day of week.  */
 342           rp_longest = NULL;
 343           decided_longest = s.decided;
 344           cnt_longest = -1;
 345           for (cnt = 0; cnt < 7; ++cnt)
 346             {
 347               const char *trp;
 348 #ifdef _NL_CURRENT
 349               if (s.decided !=raw)
 350                 {
 351                   trp = rp;
 352                   if (match_string (_NL_CURRENT (LC_TIME, DAY_1 + cnt), trp)
 353                       && trp > rp_longest)
 354                     {
 355                       rp_longest = trp;
 356                       cnt_longest = cnt;
 357                       if (s.decided == not
 358                           && strcmp (_NL_CURRENT (LC_TIME, DAY_1 + cnt),
 359                                      weekday_name[cnt]))
 360                         decided_longest = loc;
 361                     }
 362                   trp = rp;
 363                   if (match_string (_NL_CURRENT (LC_TIME, ABDAY_1 + cnt), trp)
 364                       && trp > rp_longest)
 365                     {
 366                       rp_longest = trp;
 367                       cnt_longest = cnt;
 368                       if (s.decided == not
 369                           && strcmp (_NL_CURRENT (LC_TIME, ABDAY_1 + cnt),
 370                                      ab_weekday_name[cnt]))
 371                         decided_longest = loc;
 372                     }
 373                 }
 374 #endif
 375               if (s.decided != loc
 376                   && (((trp = rp, match_string (weekday_name[cnt], trp))
 377                        && trp > rp_longest)
 378                       || ((trp = rp, match_string (ab_weekday_name[cnt], rp))
 379                           && trp > rp_longest)))
 380                 {
 381                   rp_longest = trp;
 382                   cnt_longest = cnt;
 383                   decided_longest = raw;
 384                 }
 385             }
 386           if (rp_longest == NULL)
 387             /* Does not match a weekday name.  */
 388             return NULL;
 389           rp = rp_longest;
 390           s.decided = decided_longest;
 391           tm->tm_wday = cnt_longest;
 392           s.have_wday = 1;
 393           break;
 394         case 'b':
 395         case 'B':
 396         case 'h':
 397           /* Match month name.  */
 398           rp_longest = NULL;
 399           decided_longest = s.decided;
 400           cnt_longest = -1;
 401           for (cnt = 0; cnt < 12; ++cnt)
 402             {
 403               const char *trp;
 404 #ifdef _NL_CURRENT
 405               if (s.decided !=raw)
 406                 {
 407                   trp = rp;
 408                   if (match_string (_NL_CURRENT (LC_TIME, MON_1 + cnt), trp)
 409                       && trp > rp_longest)
 410                     {
 411                       rp_longest = trp;
 412                       cnt_longest = cnt;
 413                       if (s.decided == not
 414                           && strcmp (_NL_CURRENT (LC_TIME, MON_1 + cnt),
 415                                      month_name[cnt]))
 416                         decided_longest = loc;
 417                     }
 418                   trp = rp;
 419                   if (match_string (_NL_CURRENT (LC_TIME, ABMON_1 + cnt), trp)
 420                       && trp > rp_longest)
 421                     {
 422                       rp_longest = trp;
 423                       cnt_longest = cnt;
 424                       if (s.decided == not
 425                           && strcmp (_NL_CURRENT (LC_TIME, ABMON_1 + cnt),
 426                                      ab_month_name[cnt]))
 427                         decided_longest = loc;
 428                     }
 429 #ifdef _LIBC
 430                   /* Now check the alt month.  */
 431                   trp = rp;
 432                   if (match_string (_NL_CURRENT (LC_TIME, ALTMON_1 + cnt), trp)
 433                       && trp > rp_longest)
 434                     {
 435                       rp_longest = trp;
 436                       cnt_longest = cnt;
 437                       if (s.decided == not
 438                           && strcmp (_NL_CURRENT (LC_TIME, ALTMON_1 + cnt),
 439                                      alt_month_name[cnt]))
 440                         decided_longest = loc;
 441                     }
 442                   trp = rp;
 443                   if (match_string (_NL_CURRENT (LC_TIME, _NL_ABALTMON_1 + cnt),
 444                                     trp)
 445                       && trp > rp_longest)
 446                     {
 447                       rp_longest = trp;
 448                       cnt_longest = cnt;
 449                       if (s.decided == not
 450                           && strcmp (_NL_CURRENT (LC_TIME, _NL_ABALTMON_1 + cnt),
 451                                      alt_month_name[cnt]))
 452                         decided_longest = loc;
 453                     }
 454 #endif
 455                 }
 456 #endif
 457               if (s.decided != loc
 458                   && (((trp = rp, match_string (month_name[cnt], trp))
 459                        && trp > rp_longest)
 460                       || ((trp = rp, match_string (ab_month_name[cnt], trp))
 461                           && trp > rp_longest)
 462 #ifdef _LIBC
 463                       || ((trp = rp, match_string (alt_month_name[cnt], trp))
 464                           && trp > rp_longest)
 465                       || ((trp = rp, match_string (ab_alt_month_name[cnt], trp))
 466                           && trp > rp_longest)
 467 #endif
 468               ))
 469                 {
 470                   rp_longest = trp;
 471                   cnt_longest = cnt;
 472                   decided_longest = raw;
 473                 }
 474             }
 475           if (rp_longest == NULL)
 476             /* Does not match a month name.  */
 477             return NULL;
 478           rp = rp_longest;
 479           s.decided = decided_longest;
 480           tm->tm_mon = cnt_longest;
 481           s.have_mon = 1;
 482           s.want_xday = 1;
 483           break;
 484         case 'c':
 485           /* Match locale's date and time format.  */
 486 #ifdef _NL_CURRENT
 487           if (s.decided != raw)
 488             {
 489               if (!recursive (_NL_CURRENT (LC_TIME, D_T_FMT)))
 490                 {
 491                   if (s.decided == loc)
 492                     return NULL;
 493                   else
 494                     rp = rp_backup;
 495                 }
 496               else
 497                 {
 498                   if (s.decided == not
 499                       && strcmp (_NL_CURRENT (LC_TIME, D_T_FMT), HERE_D_T_FMT))
 500                     s.decided = loc;
 501                   s.want_xday = 1;
 502                   break;
 503                 }
 504               s.decided = raw;
 505             }
 506 #endif
 507           if (!recursive (HERE_D_T_FMT))
 508             return NULL;
 509           s.want_xday = 1;
 510           break;
 511         case 'C':
 512           /* Match century number.  */
 513         match_century:
 514           get_number (0, 99, 2);
 515           s.century = val;
 516           s.want_xday = 1;
 517           break;
 518         case 'd':
 519         case 'e':
 520           /* Match day of month.  */
 521           get_number (1, 31, 2);
 522           tm->tm_mday = val;
 523           s.have_mday = 1;
 524           s.want_xday = 1;
 525           break;
 526         case 'F':
 527           if (!recursive ("%Y-%m-%d"))
 528             return NULL;
 529           s.want_xday = 1;
 530           break;
 531         case 'x':
 532 #ifdef _NL_CURRENT
 533           if (s.decided != raw)
 534             {
 535               if (!recursive (_NL_CURRENT (LC_TIME, D_FMT)))
 536                 {
 537                   if (s.decided == loc)
 538                     return NULL;
 539                   else
 540                     rp = rp_backup;
 541                 }
 542               else
 543                 {
 544                   if (s.decided == not
 545                       && strcmp (_NL_CURRENT (LC_TIME, D_FMT), HERE_D_FMT))
 546                     s.decided = loc;
 547                   s.want_xday = 1;
 548                   break;
 549                 }
 550               s.decided = raw;
 551             }
 552 #endif
 553           /* Fall through.  */
 554         case 'D':
 555           /* Match standard day format.  */
 556           if (!recursive (HERE_D_FMT))
 557             return NULL;
 558           s.want_xday = 1;
 559           break;
 560         case 'k':
 561         case 'H':
 562           /* Match hour in 24-hour clock.  */
 563           get_number (0, 23, 2);
 564           tm->tm_hour = val;
 565           s.have_I = 0;
 566           break;
 567         case 'l':
 568           /* Match hour in 12-hour clock.  GNU extension.  */
 569         case 'I':
 570           /* Match hour in 12-hour clock.  */
 571           get_number (1, 12, 2);
 572           tm->tm_hour = val % 12;
 573           s.have_I = 1;
 574           break;
 575         case 'j':
 576           /* Match day number of year.  */
 577           get_number (1, 366, 3);
 578           tm->tm_yday = val - 1;
 579           s.have_yday = 1;
 580           break;
 581         case 'm':
 582           /* Match number of month.  */
 583           get_number (1, 12, 2);
 584           tm->tm_mon = val - 1;
 585           s.have_mon = 1;
 586           s.want_xday = 1;
 587           break;
 588         case 'M':
 589           /* Match minute.  */
 590           get_number (0, 59, 2);
 591           tm->tm_min = val;
 592           break;
 593         case 'n':
 594         case 't':
 595           /* Match any white space.  */
 596           while (ISSPACE (*rp))
 597             ++rp;
 598           break;
 599         case 'p':
 600           /* Match locale's equivalent of AM/PM.  */
 601 #ifdef _NL_CURRENT
 602           if (s.decided != raw)
 603             {
 604               if (match_string (_NL_CURRENT (LC_TIME, AM_STR), rp))
 605                 {
 606                   if (strcmp (_NL_CURRENT (LC_TIME, AM_STR), HERE_AM_STR))
 607                     s.decided = loc;
 608                   s.is_pm = 0;
 609                   break;
 610                 }
 611               if (match_string (_NL_CURRENT (LC_TIME, PM_STR), rp))
 612                 {
 613                   if (strcmp (_NL_CURRENT (LC_TIME, PM_STR), HERE_PM_STR))
 614                     s.decided = loc;
 615                   s.is_pm = 1;
 616                   break;
 617                 }
 618               s.decided = raw;
 619             }
 620 #endif
 621           if (!match_string (HERE_AM_STR, rp))
 622             {
 623               if (match_string (HERE_PM_STR, rp))
 624                 s.is_pm = 1;
 625               else
 626                 return NULL;
 627             }
 628           else
 629             s.is_pm = 0;
 630           break;
 631         case 'r':
 632 #ifdef _NL_CURRENT
 633           if (s.decided != raw)
 634             {
 635               if (!recursive (_NL_CURRENT (LC_TIME, T_FMT_AMPM)))
 636                 {
 637                   if (s.decided == loc)
 638                     return NULL;
 639                   else
 640                     rp = rp_backup;
 641                 }
 642               else
 643                 {
 644                   if (s.decided == not
 645                       && strcmp (_NL_CURRENT (LC_TIME, T_FMT_AMPM),
 646                                  HERE_T_FMT_AMPM))
 647                     s.decided = loc;
 648                   break;
 649                 }
 650               s.decided = raw;
 651             }
 652 #endif
 653           if (!recursive (HERE_T_FMT_AMPM))
 654             return NULL;
 655           break;
 656         case 'R':
 657           if (!recursive ("%H:%M"))
 658             return NULL;
 659           break;
 660         case 's':
 661           {
 662             /* The number of seconds may be very high so we cannot use
 663                the `get_number' macro.  Instead read the number
 664                character for character and construct the result while
 665                doing this.  */
 666             time_t secs = 0;
 667             if (*rp < '0' || *rp > '9')
 668               /* We need at least one digit.  */
 669               return NULL;
 670
 671             do
 672               {
 673                 secs *= 10;
 674                 secs += *rp++ - '0';
 675               }
 676             while (*rp >= '0' && *rp <= '9');
 677
 678             if (localtime_r (&secs, tm) == NULL)
 679               /* Error in function.  */
 680               return NULL;
 681           }
 682           break;
 683         case 'S':
 684           get_number (0, 61, 2);
 685           tm->tm_sec = val;
 686           break;
 687         case 'X':
 688 #ifdef _NL_CURRENT
 689           if (s.decided != raw)
 690             {
 691               if (!recursive (_NL_CURRENT (LC_TIME, T_FMT)))
 692                 {
 693                   if (s.decided == loc)
 694                     return NULL;
 695                   else
 696                     rp = rp_backup;
 697                 }
 698               else
 699                 {
 700                   if (strcmp (_NL_CURRENT (LC_TIME, T_FMT), HERE_T_FMT))
 701                     s.decided = loc;
 702                   break;
 703                 }
 704               s.decided = raw;
 705             }
 706 #endif
 707           /* Fall through.  */
 708         case 'T':
 709           if (!recursive (HERE_T_FMT))
 710             return NULL;
 711           break;
 712         case 'u':
 713           get_number (1, 7, 1);
 714           tm->tm_wday = val % 7;
 715           s.have_wday = 1;
 716           break;
 717         case 'g':
 718           get_number (0, 99, 2);
 719           /* XXX This cannot determine any field in TM.  */
 720           break;
 721         case 'G':
 722           if (*rp < '0' || *rp > '9')
 723             return NULL;
 724           /* XXX Ignore the number since we would need some more
 725              information to compute a real date.  */
 726           do
 727             ++rp;
 728           while (*rp >= '0' && *rp <= '9');
 729           break;
 730         case 'U':
 731           get_number (0, 53, 2);
 732           s.week_no = val;
 733           s.have_uweek = 1;
 734           break;
 735         case 'W':
 736           get_number (0, 53, 2);
 737           s.week_no = val;
 738           s.have_wweek = 1;
 739           break;
 740         case 'V':
 741           get_number (0, 53, 2);
 742           /* XXX This cannot determine any field in TM without some
 743              information.  */
 744           break;
 745         case 'w':
 746           /* Match number of weekday.  */
 747           get_number (0, 6, 1);
 748           tm->tm_wday = val;
 749           s.have_wday = 1;
 750           break;
 751         case 'y':
 752         match_year_in_century:
 753           /* Match year within century.  */
 754           get_number (0, 99, 2);
 755           /* The "Year 2000: The Millennium Rollover" paper suggests that
 756              values in the range 69-99 refer to the twentieth century.  */
 757           tm->tm_year = val >= 69 ? val : val + 100;
 758           /* Indicate that we want to use the century, if specified.  */
 759           s.want_century = 1;
 760           s.want_xday = 1;
 761           break;
 762         case 'Y':
 763           /* Match year including century number.  */
 764           get_number (0, 9999, 4);
 765           tm->tm_year = val - 1900;
 766           s.want_century = 0;
 767           s.want_xday = 1;
 768           break;
 769         case 'Z':
 770           /* Read timezone but perform no conversion.  */
 771           while (ISSPACE (*rp))
 772             rp++;
 773           while (!ISSPACE (*rp) && *rp != '\0')
 774             rp++;
 775           break;
 776         case 'z':
 777           /* We recognize four formats:
 778              1. Two digits specify hours.
 779              2. Four digits specify hours and minutes.
 780              3. Two digits, ':', and two digits specify hours and minutes.
 781              4. 'Z' is equivalent to +0000.  */
 782           {
 783             val = 0;
 784             while (ISSPACE (*rp))
 785               ++rp;
 786             if (*rp == 'Z')
 787               {
 788                 ++rp;
 789                 tm->tm_gmtoff = 0;
 790                 break;
 791               }
 792             if (*rp != '+' && *rp != '-')
 793               return NULL;
 794             bool neg = *rp++ == '-';
 795             int n = 0;
 796             while (n < 4 && *rp >= '0' && *rp <= '9')
 797               {
 798                 val = val * 10 + *rp++ - '0';
 799                 ++n;
 800                 if (*rp == ':' && n == 2 && isdigit (*(rp + 1)))
 801                   ++rp;
 802               }
 803             if (n == 2)
 804               val *= 100;
 805             else if (n != 4)
 806               /* Only two or four digits recognized.  */
 807               return NULL;
 808             else if (val % 100 >= 60)
 809               /* Minutes valid range is 0 through 59.  */
 810               return NULL;
 811             tm->tm_gmtoff = (val / 100) * 3600 + (val % 100) * 60;
 812             if (neg)
 813               tm->tm_gmtoff = -tm->tm_gmtoff;
 814           }
 815           break;
 816         case 'E':
 817 #ifdef _NL_CURRENT
 818           switch (*fmt++)
 819             {
 820             case 'c':
 821               /* Match locale's alternate date and time format.  */
 822               if (s.decided != raw)
 823                 {
 824                   const char *fmt = _NL_CURRENT (LC_TIME, ERA_D_T_FMT);
 825
 826                   if (*fmt == '\0')
 827                     fmt = _NL_CURRENT (LC_TIME, D_T_FMT);
 828
 829                   if (!recursive (fmt))
 830                     {
 831                       if (s.decided == loc)
 832                         return NULL;
 833                       else
 834                         rp = rp_backup;
 835                     }
 836                   else
 837                     {
 838                       if (strcmp (fmt, HERE_D_T_FMT))
 839                         s.decided = loc;
 840                       s.want_xday = 1;
 841                       break;
 842                     }
 843                   s.decided = raw;
 844                 }
 845               /* The C locale has no era information, so use the
 846                  normal representation.  */
 847               if (!recursive (HERE_D_T_FMT))
 848                 return NULL;
 849               s.want_xday = 1;
 850               break;
 851             case 'C':
 852               if (s.decided != raw)
 853                 {
 854                   if (s.era_cnt >= 0)
 855                     {
 856                       era = _nl_select_era_entry (s.era_cnt HELPER_LOCALE_ARG);
 857                       if (era != NULL && match_string (era->era_name, rp))
 858                         {
 859                           s.decided = loc;
 860                           break;
 861                         }
 862                       else
 863                         return NULL;
 864                     }
 865
 866                   num_eras = _NL_CURRENT_WORD (LC_TIME,
 867                                                _NL_TIME_ERA_NUM_ENTRIES);
 868                   for (s.era_cnt = 0; s.era_cnt < (int) num_eras;
 869                        ++s.era_cnt, rp = rp_backup)
 870                     {
 871                       era = _nl_select_era_entry (s.era_cnt
 872                                                   HELPER_LOCALE_ARG);
 873                       if (era != NULL && match_string (era->era_name, rp))
 874                         {
 875                           s.decided = loc;
 876                           break;
 877                         }
 878                     }
 879                   if (s.era_cnt != (int) num_eras)
 880                     break;
 881
 882                   s.era_cnt = -1;
 883                   if (s.decided == loc)
 884                     return NULL;
 885
 886                   s.decided = raw;
 887                 }
 888               /* The C locale has no era information, so use the
 889                  normal representation.  */
 890               goto match_century;
 891             case 'y':
 892               if (s.decided != raw)
 893                 {
 894                   get_number(0, 9999, 4);
 895                   tm->tm_year = val;
 896                   s.want_era = 1;
 897                   s.want_xday = 1;
 898                   s.want_century = 1;
 899
 900                   if (s.era_cnt >= 0)
 901                     {
 902                       assert (s.decided == loc);
 903
 904                       era = _nl_select_era_entry (s.era_cnt HELPER_LOCALE_ARG);
 905                       bool match = false;
 906                       if (era != NULL)
 907                         {
 908                           int delta = ((tm->tm_year - era->offset)
 909                                        * era->absolute_direction);
 910                           /* The difference between two sets of years
 911                              does not include the final year itself,
 912                              therefore add 1 to the difference to
 913                              account for that final year.  */
 914                           match = (delta >= 0
 915                                    && delta < (((int64_t) era->stop_date[0]
 916                                                 - (int64_t) era->start_date[0])
 917                                                * era->absolute_direction
 918                                                + 1));
 919                         }
 920                       if (! match)
 921                         return NULL;
 922
 923                       break;
 924                     }
 925
 926                   num_eras = _NL_CURRENT_WORD (LC_TIME,
 927                                                _NL_TIME_ERA_NUM_ENTRIES);
 928                   for (s.era_cnt = 0; s.era_cnt < (int) num_eras; ++s.era_cnt)
 929                     {
 930                       era = _nl_select_era_entry (s.era_cnt
 931                                                   HELPER_LOCALE_ARG);
 932                       if (era != NULL)
 933                         {
 934                           int delta = ((tm->tm_year - era->offset)
 935                                        * era->absolute_direction);
 936                           /* See comment above about year difference + 1.  */
 937                           if (delta >= 0
 938                               && delta < (((int64_t) era->stop_date[0]
 939                                            - (int64_t) era->start_date[0])
 940                                           * era->absolute_direction
 941                                           + 1))
 942                             {
 943                               s.decided = loc;
 944                               break;
 945                             }
 946                         }
 947                     }
 948                   if (s.era_cnt != (int) num_eras)
 949                     break;
 950
 951                   s.era_cnt = -1;
 952                   if (s.decided == loc)
 953                     return NULL;
 954
 955                   s.decided = raw;
 956                 }
 957
 958               goto match_year_in_century;
 959             case 'Y':
 960               if (s.decided != raw)
 961                 {
 962                   num_eras = _NL_CURRENT_WORD (LC_TIME,
 963                                                _NL_TIME_ERA_NUM_ENTRIES);
 964                   for (s.era_cnt = 0; s.era_cnt < (int) num_eras;
 965                        ++s.era_cnt, rp = rp_backup)
 966                     {
 967                       era = _nl_select_era_entry (s.era_cnt HELPER_LOCALE_ARG);
 968                       if (era != NULL && recursive (era->era_format))
 969                         break;
 970                     }
 971                   if (s.era_cnt == (int) num_eras)
 972                     {
 973                       s.era_cnt = -1;
 974                       if (s.decided == loc)
 975                         return NULL;
 976                       else
 977                         rp = rp_backup;
 978                     }
 979                   else
 980                     {
 981                       s.decided = loc;
 982                       break;
 983                     }
 984
 985                   s.decided = raw;
 986                 }
 987               get_number (0, 9999, 4);
 988               tm->tm_year = val - 1900;
 989               s.want_century = 0;
 990               s.want_xday = 1;
 991               break;
 992             case 'x':
 993               if (s.decided != raw)
 994                 {
 995                   const char *fmt = _NL_CURRENT (LC_TIME, ERA_D_FMT);
 996
 997                   if (*fmt == '\0')
 998                     fmt = _NL_CURRENT (LC_TIME, D_FMT);
 999
1000                   if (!recursive (fmt))
1001                     {
1002                       if (s.decided == loc)
1003                         return NULL;
1004                       else
1005                         rp = rp_backup;
1006                     }
1007                   else
1008                     {
1009                       if (strcmp (fmt, HERE_D_FMT))
1010                         s.decided = loc;
1011                       break;
1012                     }
1013                   s.decided = raw;
1014                 }
1015               if (!recursive (HERE_D_FMT))
1016                 return NULL;
1017               break;
1018             case 'X':
1019               if (s.decided != raw)
1020                 {
1021                   const char *fmt = _NL_CURRENT (LC_TIME, ERA_T_FMT);
1022
1023                   if (*fmt == '\0')
1024                     fmt = _NL_CURRENT (LC_TIME, T_FMT);
1025
1026                   if (!recursive (fmt))
1027                     {
1028                       if (s.decided == loc)
1029                         return NULL;
1030                       else
1031                         rp = rp_backup;
1032                     }
1033                   else
1034                     {
1035                       if (strcmp (fmt, HERE_T_FMT))
1036                         s.decided = loc;
1037                       break;
1038                     }
1039                   s.decided = raw;
1040                 }
1041               if (!recursive (HERE_T_FMT))
1042                 return NULL;
1043               break;
1044             default:
1045               return NULL;
1046             }
1047           break;
1048 #else
1049           /* We have no information about the era format.  Just use
1050              the normal format.  */
1051           if (*fmt != 'c' && *fmt != 'C' && *fmt != 'y' && *fmt != 'Y'
1052               && *fmt != 'x' && *fmt != 'X')
1053             /* This is an illegal format.  */
1054             return NULL;
1055
1056           goto start_over;
1057 #endif
1058         case 'O':
1059           switch (*fmt++)
1060             {
1061             case 'b':
1062             case 'B':
1063             case 'h':
1064               /* Match month name.  Reprocess as plain 'B'.  */
1065               fmt--;
1066               goto start_over;
1067             case 'd':
1068             case 'e':
1069               /* Match day of month using alternate numeric symbols.  */
1070               get_alt_number (1, 31, 2);
1071               tm->tm_mday = val;
1072               s.have_mday = 1;
1073               s.want_xday = 1;
1074               break;
1075             case 'H':
1076               /* Match hour in 24-hour clock using alternate numeric
1077                  symbols.  */
1078               get_alt_number (0, 23, 2);
1079               tm->tm_hour = val;
1080               s.have_I = 0;
1081               break;
1082             case 'I':
1083               /* Match hour in 12-hour clock using alternate numeric
1084                  symbols.  */
1085               get_alt_number (1, 12, 2);
1086               tm->tm_hour = val % 12;
1087               s.have_I = 1;
1088               break;
1089             case 'm':
1090               /* Match month using alternate numeric symbols.  */
1091               get_alt_number (1, 12, 2);
1092               tm->tm_mon = val - 1;
1093               s.have_mon = 1;
1094               s.want_xday = 1;
1095               break;
1096             case 'M':
1097               /* Match minutes using alternate numeric symbols.  */
1098               get_alt_number (0, 59, 2);
1099               tm->tm_min = val;
1100               break;
1101             case 'S':
1102               /* Match seconds using alternate numeric symbols.  */
1103               get_alt_number (0, 61, 2);
1104               tm->tm_sec = val;
1105               break;
1106             case 'U':
1107               get_alt_number (0, 53, 2);
1108               s.week_no = val;
1109               s.have_uweek = 1;
1110               break;
1111             case 'W':
1112               get_alt_number (0, 53, 2);
1113               s.week_no = val;
1114               s.have_wweek = 1;
1115               break;
1116             case 'V':
1117               get_alt_number (0, 53, 2);
1118               /* XXX This cannot determine any field in TM without
1119                  further information.  */
1120               break;
1121             case 'w':
1122               /* Match number of weekday using alternate numeric symbols.  */
1123               get_alt_number (0, 6, 1);
1124               tm->tm_wday = val;
1125               s.have_wday = 1;
1126               break;
1127             case 'y':
1128               /* Match year within century using alternate numeric symbols.  */
1129               get_alt_number (0, 99, 2);
1130               tm->tm_year = val >= 69 ? val : val + 100;
1131               s.want_xday = 1;
1132               break;
1133             default:
1134               return NULL;
1135             }
1136           break;
1137         default:
1138           return NULL;
1139         }
1140     }
1141
1142   if (statep != NULL)
1143     {
1144       /* Recursive invocation, returning success, so
1145          update parent's struct tm and state.  */
1146       *(struct __strptime_state *) statep = s;
1147       *tmp = tmb;
1148       return (char *) rp;
1149     }
1150
1151   if (s.have_I && s.is_pm)
1152     tm->tm_hour += 12;
1153
1154   if (s.century != -1)
1155     {
1156       if (s.want_century)
1157         tm->tm_year = tm->tm_year % 100 + (s.century - 19) * 100;
1158       else
1159         /* Only the century, but not the year.  Strange, but so be it.  */
1160         tm->tm_year = (s.century - 19) * 100;
1161     }
1162
1163   if (s.era_cnt != -1)
1164     {
1165       era = _nl_select_era_entry (s.era_cnt HELPER_LOCALE_ARG);
1166       if (era == NULL)
1167         return NULL;
1168       if (s.want_era)
1169         tm->tm_year = (era->start_date[0]
1170                        + ((tm->tm_year - era->offset)
1171                           * era->absolute_direction));
1172       else
1173         /* Era start year assumed.  */
1174         tm->tm_year = era->start_date[0];
1175     }
1176   else
1177     if (s.want_era)
1178       {
1179         /* No era found but we have seen an E modifier.  Rectify some
1180            values.  */
1181         if (s.want_century && s.century == -1 && tm->tm_year < 69)
1182           tm->tm_year += 100;
1183       }
1184
1185   if (s.want_xday && !s.have_wday)
1186     {
1187       if ( !(s.have_mon && s.have_mday) && s.have_yday)
1188         {
1189           /* We don't have tm_mon and/or tm_mday, compute them.  */
1190           int t_mon = 0;
1191           while (__mon_yday[__isleap(1900 + tm->tm_year)][t_mon] <= tm->tm_yday)
1192               t_mon++;
1193           if (!s.have_mon)
1194               tm->tm_mon = t_mon - 1;
1195           if (!s.have_mday)
1196               tm->tm_mday =
1197                 (tm->tm_yday
1198                  - __mon_yday[__isleap(1900 + tm->tm_year)][t_mon - 1] + 1);
1199           s.have_mon = 1;
1200           s.have_mday = 1;
1201         }
1202       /* Don't crash in day_of_the_week if tm_mon is uninitialized.  */
1203       if (s.have_mon || (unsigned) tm->tm_mon <= 11)
1204         day_of_the_week (tm);
1205     }
1206
1207   if (s.want_xday && !s.have_yday && (s.have_mon || (unsigned) tm->tm_mon <= 11))
1208     day_of_the_year (tm);
1209
1210   if ((s.have_uweek || s.have_wweek) && s.have_wday)
1211     {
1212       int save_wday = tm->tm_wday;
1213       int save_mday = tm->tm_mday;
1214       int save_mon = tm->tm_mon;
1215       int w_offset = s.have_uweek ? 0 : 1;
1216
1217       tm->tm_mday = 1;
1218       tm->tm_mon = 0;
1219       day_of_the_week (tm);
1220       if (s.have_mday)
1221         tm->tm_mday = save_mday;
1222       if (s.have_mon)
1223         tm->tm_mon = save_mon;
1224
1225       if (!s.have_yday)
1226         tm->tm_yday = ((7 - (tm->tm_wday - w_offset)) % 7
1227                        + (s.week_no - 1) * 7
1228                        + (save_wday - w_offset + 7) % 7);
1229
1230       if (!s.have_mday || !s.have_mon)
1231         {
1232           int t_mon = 0;
1233           while (__mon_yday[__isleap(1900 + tm->tm_year)][t_mon]
1234                  <= tm->tm_yday)
1235             t_mon++;
1236           if (!s.have_mon)
1237             tm->tm_mon = t_mon - 1;
1238           if (!s.have_mday)
1239               tm->tm_mday =
1240                 (tm->tm_yday
1241                  - __mon_yday[__isleap(1900 + tm->tm_year)][t_mon - 1] + 1);
1242         }
1243
1244       tm->tm_wday = save_wday;
1245     }
1246
1247   return (char *) rp;
1248 }
1249
1250
1251 char *
1252 strptime (const char *buf, const char *format, struct tm *tm LOCALE_PARAM)
1253 {
1254   return __strptime_internal (buf, format, tm, NULL LOCALE_ARG);
1255 }
1256
1257 #ifdef _LIBC
1258 weak_alias (__strptime_l, strptime_l)
1259 #endif