(compute_change): Replace slow loop to compute T by simple algorithm.
[kopensolaris-gnu/glibc.git] / time / strptime.c
index 8d65071..5f8271e 100644 (file)
@@ -1,5 +1,5 @@
 /* Convert a string representation of time to a time value.
-   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
 
 # endif  /* GCC.  */
 #endif  /* Not __P.  */
 
-#if ! HAVE_LOCALTIME_R && ! defined (localtime_r)
-#ifdef _LIBC
-#define localtime_r __localtime_r
-#else
+
+#if ! HAVE_LOCALTIME_R && ! defined localtime_r
+# ifdef _LIBC
+#  define localtime_r __localtime_r
+# else
 /* Approximate localtime_r as best we can in its absence.  */
-#define localtime_r my_localtime_r
+#  define localtime_r my_localtime_r
 static struct tm *localtime_r __P ((const time_t *, struct tm *));
 static struct tm *
 localtime_r (t, tp)
@@ -64,7 +65,7 @@ localtime_r (t, tp)
   *tp = *l;
   return tp;
 }
-#endif /* ! _LIBC */
+# endif /* ! _LIBC */
 #endif /* ! HAVE_LOCALTIME_R && ! defined (localtime_r) */
 
 
@@ -82,50 +83,71 @@ localtime_r (t, tp)
 #endif
 /* We intentionally do not use isdigit() for testing because this will
    lead to problems with the wide character version.  */
-#define get_number(from, to) \
+#define get_number(from, to, n) \
   do {                                                                       \
+    int __n = n;                                                             \
     val = 0;                                                                 \
+    while (*rp == ' ')                                                       \
+      ++rp;                                                                  \
     if (*rp < '0' || *rp > '9')                                                      \
       return NULL;                                                           \
     do {                                                                     \
       val *= 10;                                                             \
       val += *rp++ - '0';                                                    \
-    } while (val * 10 <= to && *rp >= '0' && *rp <= '9');                    \
+    } while (--__n > 0 && val * 10 <= to && *rp >= '0' && *rp <= '9');       \
     if (val < from || val > to)                                                      \
       return NULL;                                                           \
   } while (0)
 #ifdef _NL_CURRENT
-# define get_alt_number(from, to) \
-  do {                                                                       \
+# define get_alt_number(from, to, n) \
+  ({                                                                         \
+    __label__ do_normal;                                                     \
     if (*decided != raw)                                                     \
       {                                                                              \
        const char *alts = _NL_CURRENT (LC_TIME, ALT_DIGITS);                 \
+       int __n = n;                                                          \
+       int any = 0;                                                          \
+       while (*rp == ' ')                                                    \
+         ++rp;                                                               \
        val = 0;                                                              \
-       while (*alts != '\0')                                                 \
-         {                                                                   \
-           size_t len = strlen (alts);                                       \
-           if (strncasecmp (alts, rp, len) == 0)                             \
+       do {                                                                  \
+         val *= 10;                                                          \
+         while (*alts != '\0')                                               \
+           {                                                                 \
+             size_t len = strlen (alts);                                     \
+             if (strncasecmp (alts, rp, len) == 0)                           \
+               break;                                                        \
+             alts += len + 1;                                                \
+             ++val;                                                          \
+           }                                                                 \
+         if (*alts == '\0')                                                  \
+           {                                                                 \
+             if (*decided == not && ! any)                                   \
+               goto do_normal;                                               \
+             /* If we haven't read anything it's an error.  */               \
+             if (! any)                                                      \
+               return NULL;                                                  \
+             /* Correct the premature multiplication.  */                    \
+             val /= 10;                                                      \
              break;                                                          \
-           alts = strchr (alts, '\0') + 1;                                   \
-           ++val;                                                            \
-         }                                                                   \
-       if (*alts == '\0')                                                    \
-         {                                                                   \
-           if (*decided == loc && val != 0)                                  \
-             return NULL;                                                    \
-         }                                                                   \
-       else                                                                  \
-         {                                                                   \
+           }                                                                 \
+         else                                                                \
            *decided = loc;                                                   \
-           break;                                                            \
-         }                                                                   \
+       } while (--__n > 0 && val * 10 <= to);                                \
+       if (val < from || val > to)                                           \
+         return NULL;                                                        \
       }                                                                              \
-    get_number (from, to);                                                   \
-  } while (0)
+    else                                                                     \
+      {                                                                              \
+       do_normal:                                                            \
+        get_number (from, to, n);                                            \
+      }                                                                              \
+    0;                                                                       \
+  })
 #else
-# define get_alt_number(from, to) \
+# define get_alt_number(from, to, n) \
   /* We don't have the alternate representation.  */                         \
-  get_number(from, to)
+  get_number(from, to, n)
 #endif
 #define recursive(new_fmt) \
   (*(new_fmt) != '\0'                                                        \
@@ -135,6 +157,7 @@ localtime_r (t, tp)
 #ifdef _LIBC
 /* This is defined in locale/C-time.c in the GNU libc.  */
 extern const struct locale_data _nl_C_LC_TIME;
+extern const unsigned short int __mon_yday[2][13];
 
 # define weekday_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (DAY_1)].string)
 # define ab_weekday_name \
@@ -142,12 +165,14 @@ extern const struct locale_data _nl_C_LC_TIME;
 # define month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (MON_1)].string)
 # define ab_month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABMON_1)].string)
 # define HERE_D_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_T_FMT)].string)
-# define HERE_D_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_T_FMT)].string)
+# define HERE_D_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_FMT)].string)
 # define HERE_AM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (AM_STR)].string)
 # define HERE_PM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (PM_STR)].string)
 # define HERE_T_FMT_AMPM \
   (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT_AMPM)].string)
 # define HERE_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT)].string)
+
+# define strncasecmp(s1, s2, n) __strncasecmp (s1, s2, n)
 #else
 static char const weekday_name[][10] =
   {
@@ -174,16 +199,64 @@ static char const ab_month_name[][4] =
 # define HERE_PM_STR "PM"
 # define HERE_T_FMT_AMPM "%I:%M:%S %p"
 # define HERE_T_FMT "%H:%M:%S"
+
+const unsigned short int __mon_yday[2][13] =
+  {
+    /* Normal years.  */
+    { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+    /* Leap years.  */
+    { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+  };
 #endif
 
 /* Status of lookup: do we use the locale data or the raw data?  */
 enum locale_status { not, loc, raw };
 
+
+#ifndef __isleap
+/* Nonzero if YEAR is a leap year (every 4 years,
+   except every 100th isn't, and every 400th is).  */
+# define __isleap(year)        \
+  ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
+#endif
+
+/* Compute the day of the week.  */
+static void
+day_of_the_week (struct tm *tm)
+{
+  /* We know that January 1st 1970 was a Thursday (= 4).  Compute the
+     the difference between this data in the one on TM and so determine
+     the weekday.  */
+  int corr_year = 1900 + tm->tm_year - (tm->tm_mon < 2);
+  int wday = (-473
+             + (365 * (tm->tm_year - 70))
+             + (corr_year / 4)
+             - ((corr_year / 4) / 25) + ((corr_year / 4) % 25 < 0)
+             + (((corr_year / 4) / 25) / 4)
+             + __mon_yday[0][tm->tm_mon]
+             + tm->tm_mday - 1);
+  tm->tm_wday = wday % 7;
+}
+
+/* Compute the day of the year.  */
+static void
+day_of_the_year (struct tm *tm)
+{
+  tm->tm_yday = (__mon_yday[__isleap (1900 + tm->tm_year)][tm->tm_mon]
+                + (tm->tm_mday - 1));
+}
+
 static char *
+#ifdef _LIBC
+internal_function
+#endif
 strptime_internal __P ((const char *buf, const char *format, struct tm *tm,
                        enum locale_status *decided));
 
 static char *
+#ifdef _LIBC
+internal_function
+#endif
 strptime_internal (buf, format, tm, decided)
      const char *buf;
      const char *format;
@@ -195,10 +268,17 @@ strptime_internal (buf, format, tm, decided)
   int cnt;
   size_t val;
   int have_I, is_pm;
+  int century, want_century;
+  int have_wday, want_xday;
+  int have_yday;
+  int have_mon, have_mday;
 
   rp = buf;
   fmt = format;
   have_I = is_pm = 0;
+  century = -1;
+  want_century = 0;
+  have_wday = want_xday = have_yday = have_mon = have_mday = 0;
 
   while (*fmt != '\0')
     {
@@ -269,6 +349,7 @@ strptime_internal (buf, format, tm, decided)
            /* Does not match a weekday name.  */
            return NULL;
          tm->tm_wday = cnt;
+         have_wday = 1;
          break;
        case 'b':
        case 'B':
@@ -308,6 +389,7 @@ strptime_internal (buf, format, tm, decided)
            /* Does not match a month name.  */
            return NULL;
          tm->tm_mon = cnt;
+         want_xday = 1;
          break;
        case 'c':
          /* Match locale's date and time format.  */
@@ -324,6 +406,7 @@ strptime_internal (buf, format, tm, decided)
                  if (*decided == not &&
                      strcmp (_NL_CURRENT (LC_TIME, D_T_FMT), HERE_D_T_FMT))
                    *decided = loc;
+                 want_xday = 1;
                  break;
                }
              *decided = raw;
@@ -331,17 +414,26 @@ strptime_internal (buf, format, tm, decided)
 #endif
          if (!recursive (HERE_D_T_FMT))
            return NULL;
+         want_xday = 1;
          break;
        case 'C':
          /* Match century number.  */
-         get_number (0, 99);
-         /* We don't need the number.  */
+         get_number (0, 99, 2);
+         century = val;
+         want_xday = 1;
          break;
        case 'd':
        case 'e':
          /* Match day of month.  */
-         get_number (1, 31);
+         get_number (1, 31, 2);
          tm->tm_mday = val;
+         have_mday = 1;
+         want_xday = 1;
+         break;
+       case 'F':
+         if (!recursive ("%Y-%m-%d"))
+           return NULL;
+         want_xday = 1;
          break;
        case 'x':
 #ifdef _NL_CURRENT
@@ -357,6 +449,7 @@ strptime_internal (buf, format, tm, decided)
                  if (decided == not
                      && strcmp (_NL_CURRENT (LC_TIME, D_FMT), HERE_D_FMT))
                    *decided = loc;
+                 want_xday = 1;
                  break;
                }
              *decided = raw;
@@ -367,32 +460,37 @@ strptime_internal (buf, format, tm, decided)
          /* Match standard day format.  */
          if (!recursive (HERE_D_FMT))
            return NULL;
+         want_xday = 1;
          break;
+       case 'k':
        case 'H':
          /* Match hour in 24-hour clock.  */
-         get_number (0, 23);
+         get_number (0, 23, 2);
          tm->tm_hour = val;
          have_I = 0;
          break;
        case 'I':
          /* Match hour in 12-hour clock.  */
-         get_number (1, 12);
+         get_number (1, 12, 2);
          tm->tm_hour = val % 12;
          have_I = 1;
          break;
        case 'j':
          /* Match day number of year.  */
-         get_number (1, 366);
+         get_number (1, 366, 3);
          tm->tm_yday = val - 1;
+         have_yday = 1;
          break;
        case 'm':
          /* Match number of month.  */
-         get_number (1, 12);
+         get_number (1, 12, 2);
          tm->tm_mon = val - 1;
+         have_mon = 1;
+         want_xday = 1;
          break;
        case 'M':
          /* Match minute.  */
-         get_number (0, 59);
+         get_number (0, 59, 2);
          tm->tm_min = val;
          break;
        case 'n':
@@ -461,7 +559,7 @@ strptime_internal (buf, format, tm, decided)
               the `get_number' macro.  Instead read the number
               character for character and construct the result while
               doing this.  */
-           time_t secs;
+           time_t secs = 0;
            if (*rp < '0' || *rp > '9')
              /* We need at least one digit.  */
              return NULL;
@@ -479,7 +577,7 @@ strptime_internal (buf, format, tm, decided)
          }
          break;
        case 'S':
-         get_number (0, 61);
+         get_number (0, 61, 2);
          tm->tm_sec = val;
          break;
        case 'X':
@@ -506,11 +604,12 @@ strptime_internal (buf, format, tm, decided)
            return NULL;
          break;
        case 'u':
-         get_number (1, 7);
+         get_number (1, 7, 1);
          tm->tm_wday = val % 7;
+         have_wday = 1;
          break;
        case 'g':
-         get_number (0, 99);
+         get_number (0, 99, 2);
          /* XXX This cannot determine any field in TM.  */
          break;
        case 'G':
@@ -525,27 +624,32 @@ strptime_internal (buf, format, tm, decided)
        case 'U':
        case 'V':
        case 'W':
-         get_number (0, 53);
+         get_number (0, 53, 2);
          /* XXX This cannot determine any field in TM without some
             information.  */
          break;
        case 'w':
          /* Match number of weekday.  */
-         get_number (0, 6);
+         get_number (0, 6, 1);
          tm->tm_wday = val;
+         have_wday = 1;
          break;
        case 'y':
          /* Match year within century.  */
-         get_number (0, 99);
-         tm->tm_year = val >= 50 ? val : val + 100;
+         get_number (0, 99, 2);
+         /* The "Year 2000: The Millennium Rollover" paper suggests that
+            values in the range 69-99 refer to the twentieth century.  */
+         tm->tm_year = val >= 69 ? val : val + 100;
+         /* Indicate that we want to use the century, if specified.  */
+         want_century = 1;
+         want_xday = 1;
          break;
        case 'Y':
          /* Match year including century number.  */
-         if (sizeof (time_t) > 4)
-           get_number (0, 9999);
-         else
-           get_number (0, 2036);
+         get_number (0, 9999, 4);
          tm->tm_year = val - 1900;
+         want_century = 0;
+         want_xday = 1;
          break;
        case 'Z':
          /* XXX How to handle this?  */
@@ -572,6 +676,7 @@ strptime_internal (buf, format, tm, decided)
                    {
                      if (strcmp (fmt, HERE_D_T_FMT))
                        *decided = loc;
+                     want_xday = 1;
                      break;
                    }
                  *decided = raw;
@@ -580,6 +685,7 @@ strptime_internal (buf, format, tm, decided)
                 normal representation.  */
              if (!recursive (HERE_D_T_FMT))
                return NULL;
+             want_xday = 1;
              break;
            case 'C':
            case 'y':
@@ -657,53 +763,60 @@ strptime_internal (buf, format, tm, decided)
            case 'd':
            case 'e':
              /* Match day of month using alternate numeric symbols.  */
-             get_alt_number (1, 31);
+             get_alt_number (1, 31, 2);
              tm->tm_mday = val;
+             have_mday = 1;
+             want_xday = 1;
              break;
            case 'H':
              /* Match hour in 24-hour clock using alternate numeric
                 symbols.  */
-             get_alt_number (0, 23);
+             get_alt_number (0, 23, 2);
              tm->tm_hour = val;
              have_I = 0;
              break;
            case 'I':
              /* Match hour in 12-hour clock using alternate numeric
                 symbols.  */
-             get_alt_number (1, 12);
+             get_alt_number (1, 12, 2);
              tm->tm_hour = val - 1;
              have_I = 1;
              break;
            case 'm':
              /* Match month using alternate numeric symbols.  */
-             get_alt_number (1, 12);
+             get_alt_number (1, 12, 2);
              tm->tm_mon = val - 1;
+             have_mon = 1;
+             want_xday = 1;
              break;
            case 'M':
              /* Match minutes using alternate numeric symbols.  */
-             get_alt_number (0, 59);
+             get_alt_number (0, 59, 2);
              tm->tm_min = val;
              break;
            case 'S':
              /* Match seconds using alternate numeric symbols.  */
-             get_alt_number (0, 61);
+             get_alt_number (0, 61, 2);
              tm->tm_sec = val;
              break;
            case 'U':
            case 'V':
            case 'W':
-             get_alt_number (0, 53);
+             get_alt_number (0, 53, 2);
              /* XXX This cannot determine any field in TM without
                 further information.  */
              break;
            case 'w':
              /* Match number of weekday using alternate numeric symbols.  */
-             get_alt_number (0, 6);
+             get_alt_number (0, 6, 1);
              tm->tm_wday = val;
+             have_wday = 1;
              break;
            case 'y':
              /* Match year within century using alternate numeric symbols.  */
-             get_alt_number (0, 99);
+             get_alt_number (0, 99, 2);
+             tm->tm_year = val >= 69 ? val : val + 100;
+             want_xday = 1;
              break;
            default:
              return NULL;
@@ -717,6 +830,25 @@ strptime_internal (buf, format, tm, decided)
   if (have_I && is_pm)
     tm->tm_hour += 12;
 
+  if (want_century && century != -1)
+    tm->tm_year = tm->tm_year % 100 + (century - 19) * 100;
+
+  if (want_xday && !have_wday) {
+      if ( !(have_mon && have_mday) && have_yday)  {
+         /* we don't have tm_mon and/or tm_mday, compute them */
+         int t_mon = 0;
+         while (__mon_yday[__isleap(1900 + tm->tm_year)][t_mon] <= tm->tm_yday)
+             t_mon++;
+         if (!have_mon)
+             tm->tm_mon = t_mon - 1;
+         if (!have_mday)
+             tm->tm_mday = tm->tm_yday - __mon_yday[__isleap(1900 + tm->tm_year)][t_mon - 1] + 1;
+      }
+      day_of_the_week (tm);
+  }
+  if (want_xday && !have_yday)
+    day_of_the_year (tm);
+
   return (char *) rp;
 }