lib/roken/strtoull.c

   1 /*-
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Copyright (c) 2011 The FreeBSD Foundation
   6  * All rights reserved.
   7  * Portions of this software were developed by David Chisnall
   8  * under sponsorship from the FreeBSD Foundation.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <config.h>
  36
  37 #include <string.h>
  38
  39 #include "roken.h"
  40
  41 /* #include <sys/cdefs.h> */
  42
  43 #include <limits.h>
  44 #include <errno.h>
  45 #include <ctype.h>
  46 #include <stdlib.h>
  47 #include <stdint.h>
  48
  49 /*
  50  * Convert a string to an unsigned long long integer.
  51  *
  52  * Assumes that the upper and lower case
  53  * alphabets and digits are each contiguous.
  54  */
  55 ROKEN_LIB_FUNCTION unsigned long long ROKEN_LIB_CALL
  56 strtoull(const char * nptr, char ** endptr, int base)
  57 {
  58     const char *s;
  59     unsigned long long acc;
  60     char c;
  61     unsigned long long cutoff;
  62     int neg, any, cutlim;
  63
  64     /*
  65      * See strtoq for comments as to the logic used.
  66      */
  67     s = nptr;
  68     do {
  69         c = *s++;
  70     } while (isspace((unsigned char)c));
  71     if (c == '-') {
  72         neg = 1;
  73         c = *s++;
  74     } else {
  75         neg = 0;
  76         if (c == '+')
  77             c = *s++;
  78     }
  79     if ((base == 0 || base == 16) &&
  80         c == '0' && (*s == 'x' || *s == 'X') &&
  81         ((s[1] >= '0' && s[1] <= '9') ||
  82         (s[1] >= 'A' && s[1] <= 'F') ||
  83         (s[1] >= 'a' && s[1] <= 'f'))) {
  84         c = s[1];
  85         s += 2;
  86         base = 16;
  87     }
  88     if (base == 0)
  89         base = c == '0' ? 8 : 10;
  90     acc = any = 0;
  91     if (base < 2 || base > 36)
  92         goto noconv;
  93
  94     cutoff = ULLONG_MAX / base;
  95     cutlim = ULLONG_MAX % base;
  96     for ( ; ; c = *s++) {
  97         if (c >= '0' && c <= '9')
  98             c -= '0';
  99         else if (c >= 'A' && c <= 'Z')
 100             c -= 'A' - 10;
 101         else if (c >= 'a' && c <= 'z')
 102             c -= 'a' - 10;
 103         else
 104             break;
 105         if (c >= base)
 106             break;
 107         if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 108             any = -1;
 109         else {
 110             any = 1;
 111             acc *= base;
 112             acc += c;
 113         }
 114     }
 115     if (any < 0) {
 116         acc = ULLONG_MAX;
 117         errno = ERANGE;
 118     } else if (!any) {
 119 noconv:
 120         errno = EINVAL;
 121     } else if (neg)
 122         acc = -acc;
 123     if (endptr != NULL)
 124         *endptr = (char *)(any ? s - 1 : nptr);
 125     return (acc);
 126 }
 127