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 #ifndef HAVE_STRTOULL
  42
  43 /* #include <sys/cdefs.h> */
  44
  45 #include <limits.h>
  46 #include <errno.h>
  47 #include <ctype.h>
  48 #include <stdlib.h>
  49 #include <stdint.h>
  50
  51 /*
  52  * Convert a string to an unsigned long long integer.
  53  *
  54  * Assumes that the upper and lower case
  55  * alphabets and digits are each contiguous.
  56  */
  57 ROKEN_LIB_FUNCTION unsigned long long ROKEN_LIB_CALL
  58 strtoull(const char * nptr, char ** endptr, int base)
  59 {
  60     const char *s;
  61     unsigned long long acc;
  62     char c;
  63     unsigned long long cutoff;
  64     int neg, any, cutlim;
  65
  66     /*
  67      * See strtoq for comments as to the logic used.
  68      */
  69     s = nptr;
  70     do {
  71         c = *s++;
  72     } while (isspace((unsigned char)c));
  73     if (c == '-') {
  74         neg = 1;
  75         c = *s++;
  76     } else {
  77         neg = 0;
  78         if (c == '+')
  79             c = *s++;
  80     }
  81     if ((base == 0 || base == 16) &&
  82         c == '0' && (*s == 'x' || *s == 'X') &&
  83         ((s[1] >= '0' && s[1] <= '9') ||
  84         (s[1] >= 'A' && s[1] <= 'F') ||
  85         (s[1] >= 'a' && s[1] <= 'f'))) {
  86         c = s[1];
  87         s += 2;
  88         base = 16;
  89     }
  90     if (base == 0)
  91         base = c == '0' ? 8 : 10;
  92     acc = any = 0;
  93     if (base < 2 || base > 36)
  94         goto noconv;
  95
  96     cutoff = ULLONG_MAX / base;
  97     cutlim = ULLONG_MAX % base;
  98     for ( ; ; c = *s++) {
  99         if (c >= '0' && c <= '9')
 100             c -= '0';
 101         else if (c >= 'A' && c <= 'Z')
 102             c -= 'A' - 10;
 103         else if (c >= 'a' && c <= 'z')
 104             c -= 'a' - 10;
 105         else
 106             break;
 107         if (c >= base)
 108             break;
 109         if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 110             any = -1;
 111         else {
 112             any = 1;
 113             acc *= base;
 114             acc += c;
 115         }
 116     }
 117     if (any < 0) {
 118         acc = ULLONG_MAX;
 119         errno = ERANGE;
 120     } else if (!any) {
 121 noconv:
 122         errno = EINVAL;
 123     } else if (neg)
 124         acc = -(long long)acc;
 125     if (endptr != NULL)
 126         *endptr = (char *)(any ? s - 1 : nptr);
 127     return (acc);
 128 }
 129 #endif /* !HAVE_STRTOULL */