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