reactos/lib/crtdll/stdlib/strtoll.c

   1 /* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
   2 /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
   3 #include <limits.h>
   4 #include <crtdll/ctype.h>
   5 #include <crtdll/errno.h>
   6 #include <crtdll/stdlib.h>
   7 //#include <crtdll/unconst.h>
   8
   9 /* constants used in Solaris */
  10 #define LLONG_MIN       -9223372036854775807L-1L
  11 #define LLONG_MAX       9223372036854775807L
  12 #define ULLONG_MAX      18446744073709551615UL
  13
  14 long
  15 strtoll(const char *nptr, char **endptr, int base)
  16 {
  17   const char *s = nptr;
  18   unsigned long acc;
  19   int c;
  20   unsigned long cutoff;
  21   int neg = 0, any, cutlim;
  22
  23   /*
  24    * See strtol for comments as to the logic used.
  25    */
  26   do {
  27     c = *s++;
  28   } while (isspace(c));
  29   if (c == '-')
  30   {
  31     neg = 1;
  32     c = *s++;
  33   }
  34   else if (c == '+')
  35     c = *s++;
  36   if ((base == 0 || base == 16) &&
  37       c == '0' && (*s == 'x' || *s == 'X'))
  38   {
  39     c = s[1];
  40     s += 2;
  41     base = 16;
  42   }
  43   if (base == 0)
  44     base = c == '0' ? 8 : 10;
  45
  46 /* to prevent overflow, we take max-1 and add 1 after division */
  47   cutoff = neg ? -(LLONG_MIN+1) : LLONG_MAX-1;
  48   cutlim = cutoff % base;
  49   cutoff /= base;
  50   if (++cutlim == base)
  51   {
  52     cutlim = 0;
  53     cutoff++;
  54   }
  55   for (acc = 0, any = 0;; c = *s++)
  56   {
  57     if (isdigit(c))
  58       c -= '0';
  59     else if (isalpha(c))
  60       c -= isupper(c) ? 'A' - 10 : 'a' - 10;
  61     else
  62       break;
  63     if (c >= base)
  64       break;
  65     if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
  66       any = -1;
  67     else
  68     {
  69       any = 1;
  70       acc *= base;
  71       acc += c;
  72     }
  73   }
  74   if (any < 0)
  75   {
  76     acc = neg ? LLONG_MIN : LLONG_MAX;
  77     errno = ERANGE;
  78   }
  79   else if (neg)
  80     acc *= -1;
  81   if (endptr != 0)
  82     *endptr = any ? (char *)s - 1 : (char *)nptr;
  83   return acc;
  84 }