compiler/clib/strtoull.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     ANSI C function strtoull().
   6 */
   7
   8 /* This function requires the use of the long long type. */
   9 #include <aros/system.h>
  10 #if defined(AROS_HAVE_LONG_LONG)
  11
  12 #include <ctype.h>
  13 #include <errno.h>
  14 #include <stdlib.h>
  15 #ifndef AROS_NO_LIMITS_H
  16 #       include <limits.h>
  17 #else
  18 #       define ULLONG_MAX       0xffffffffffffffffULL
  19 #endif
  20
  21 /* Function disabled because of the long long support fns not in the libs */
  22 #if 0
  23 /*****************************************************************************
  24
  25     NAME */
  26 #include <stdlib.h>
  27
  28         unsigned long long strtoull (
  29
  30 /*  SYNOPSIS */
  31         const char * restrict   str,
  32         char      ** restrict   endptr,
  33         int                     base)
  34
  35 /*  FUNCTION
  36         Convert a string of digits into an integer according to the
  37         given base.
  38
  39     INPUTS
  40         str - The string which should be converted. Leading
  41                 whitespace are ignored. The number may be prefixed
  42                 by a '+' or '-'. If base is above 10, then the
  43                 alphabetic characters from 'A' are used to specify
  44                 digits above 9 (ie. 'A' or 'a' is 10, 'B' or 'b' is
  45                 11 and so on until 'Z' or 'z' is 35).
  46         endptr - If this is non-NULL, then the address of the first
  47                 character after the number in the string is stored
  48                 here.
  49         base - The base for the number. May be 0 or between 2 and 36,
  50                 including both. 0 means to autodetect the base. strtoull()
  51                 selects the base by inspecting the first characters
  52                 of the string. If they are "0x", then base 16 is
  53                 assumed. If they are "0", then base 8 is assumed. Any
  54                 other digit will assume base 10. This is like in C.
  55
  56                 If you give base 16, then an optional "0x" may
  57                 precede the number in the string.
  58
  59     RESULT
  60         The value of the string. The first character after the number
  61         is returned in *endptr, if endptr is non-NULL. If no digits can
  62         be converted, *endptr contains str (if non-NULL) and 0 is
  63         returned.
  64
  65     NOTES
  66
  67     EXAMPLE
  68         // Returns 1, ptr points to the 0-Byte
  69         strtoull ("  \t +0x1", &ptr, 0);
  70
  71         // Returns 15. ptr points to the a
  72         strtoull ("017a", &ptr, 0);
  73
  74         // Returns 215 (5*36 + 35)
  75         strtoull ("5z", &ptr, 36);
  76
  77     BUGS
  78
  79     SEE ALSO
  80         strtoll(), strtoull()
  81
  82     INTERNALS
  83
  84 ******************************************************************************/
  85 {
  86     unsigned long long  val = 0;
  87     int                 digit;
  88     char                c = 0;
  89     unsigned long long  cutoff;
  90     int                 cutlim;
  91     int                 any;
  92
  93     if (base < 0 || base == 1 || base > 36)
  94     {
  95         errno = EINVAL;
  96
  97         if (endptr)
  98             *endptr = (char *)str;
  99
 100         return 0;
 101     }
 102
 103     while (isspace (*str))
 104         str ++;
 105
 106     if (*str)
 107     {
 108         if (*str == '+' || *str == '-')
 109             c = *str ++;
 110
 111         /* Assume base ? */
 112         if (base == 0)
 113         {
 114             if (*str == '0') /* Base 8 or 16 */
 115             {
 116                 str++;
 117                 if (*str == 'x' || *str == 'X')
 118                 {
 119                     base = 16;
 120                     str++;
 121                 }
 122                 else
 123                     base = 8;
 124             }
 125             else /* Any other digit: Base 10 (decimal) */
 126                 base = 10;
 127         }
 128
 129         /*
 130             Conversion loop, from FreeBSD's src/lib/libc/stdlib/strtoull.c
 131
 132             The previous AROS loop was
 133             a) inefficient - it did a division each time around.
 134             b) buggy - it returned the wrong value in endptr on overflow.
 135         */
 136         cutoff = (unsigned long long)ULLONG_MAX / (unsigned long long)base;
 137         cutlim = (unsigned long long)ULLONG_MAX % (unsigned long long)base;
 138         val = 0;
 139         any = 0;
 140
 141         while (*str)
 142         {
 143             digit = *str;
 144
 145             if (!isascii(digit))
 146                 break;
 147
 148             if (isdigit(digit))
 149                 digit -= '0';
 150             else if (isalpha(digit))
 151                 digit -= isupper(c) ? 'A' - 10 : 'a' - 10;
 152             else
 153                 break;
 154
 155             if (digit >= base)
 156                 break;
 157
 158             /*
 159                 any < 0 when we have overflowed. We still need to find the
 160                 end of the subject sequence
 161             */
 162             if (any < 0 || val > cutoff || (val == cutoff && digit > cutlim))
 163             {
 164                 any = -1;
 165             }
 166             else
 167             {
 168                 any = 1;
 169                 val = (val * base) + digit;
 170             }
 171
 172             str++;
 173         }
 174
 175         /* Range overflow */
 176         if (any < 0)
 177         {
 178             val = ULLONG_MAX;
 179             errno = ERANGE;
 180         }
 181
 182         if (c == '-')
 183             val = -val;
 184     }
 185
 186     if (endptr)
 187         *endptr = (char *)str;
 188
 189     return val;
 190 } /* strtoull */
 191 #else
 192 unsigned long long
 193 strtoull(const char * restrict str, char ** restrict endptr, int base)
 194 {
 195     abort();
 196 }
 197 #endif
 198 #endif /* AROS_HAVE_LONG_LONG */