src/tiff/port/strtoull.c

   1 /*-
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <limits.h>
  35 #include <errno.h>
  36 #include <ctype.h>
  37 #include <stdlib.h>
  38
  39 /*
  40  * Convert a string to an unsigned long long integer.
  41  *
  42  * Assumes that the upper and lower case
  43  * alphabets and digits are each contiguous.
  44  */
  45 unsigned long long
  46 strtoull(const char *nptr, char **endptr, int base)
  47 {
  48         const char *s;
  49         unsigned long long acc;
  50         char c;
  51         unsigned long long cutoff;
  52         int neg, any, cutlim;
  53
  54         /*
  55          * See strtoq for comments as to the logic used.
  56          */
  57         s = nptr;
  58         do {
  59                 c = *s++;
  60         } while (isspace((unsigned char)c));
  61         if (c == '-') {
  62                 neg = 1;
  63                 c = *s++;
  64         } else {
  65                 neg = 0;
  66                 if (c == '+')
  67                         c = *s++;
  68         }
  69         if ((base == 0 || base == 16) &&
  70             c == '0' && (*s == 'x' || *s == 'X') &&
  71             ((s[1] >= '0' && s[1] <= '9') ||
  72             (s[1] >= 'A' && s[1] <= 'F') ||
  73             (s[1] >= 'a' && s[1] <= 'f'))) {
  74                 c = s[1];
  75                 s += 2;
  76                 base = 16;
  77         }
  78         if (base == 0)
  79                 base = c == '0' ? 8 : 10;
  80         acc = any = 0;
  81         if (base < 2 || base > 36)
  82                 goto noconv;
  83
  84         cutoff = ULLONG_MAX / base;
  85         cutlim = ULLONG_MAX % base;
  86         for ( ; ; c = *s++) {
  87                 if (c >= '0' && c <= '9')
  88                         c -= '0';
  89                 else if (c >= 'A' && c <= 'Z')
  90                         c -= 'A' - 10;
  91                 else if (c >= 'a' && c <= 'z')
  92                         c -= 'a' - 10;
  93                 else
  94                         break;
  95                 if (c >= base)
  96                         break;
  97                 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
  98                         any = -1;
  99                 else {
 100                         any = 1;
 101                         acc *= base;
 102                         acc += c;
 103                 }
 104         }
 105         if (any < 0) {
 106                 acc = ULLONG_MAX;
 107                 errno = ERANGE;
 108         } else if (!any) {
 109 noconv:
 110                 errno = EINVAL;
 111         } else if (neg)
 112                 acc = -acc;
 113         if (endptr != NULL)
 114                 *endptr = (char *)(any ? s - 1 : nptr);
 115         return (acc);
 116 }