src/system/libroot/posix/stdlib/strtoq.c

   1 /*-
   2  * Copyright (c) 1992 The Regents of the University of California.
   3  * 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 <sys/types.h>
  35
  36 #include <ctype.h>
  37 #include <errno.h>
  38 //#include <limits.h>
  39 #include <stdlib.h>
  40
  41 #include <errno_private.h>
  42
  43
  44 #define QUAD_MIN   (-0x7fffffffffffffffLL - 1)
  45 #define QUAD_MAX   0x7fffffffffffffffLL
  46 /*
  47  * Convert a string to a quad integer.
  48  *
  49  * Ignores `locale' stuff.  Assumes that the upper and lower case
  50  * alphabets and digits are each contiguous.
  51  */
  52 int64
  53 strtoq(nptr, endptr, base)
  54         const char *nptr;
  55         char **endptr;
  56         register int base;
  57 {
  58         register const char *s;
  59         register int64 acc, cutoff;
  60         register int c;
  61         register int neg, any, cutlim;
  62
  63         /*
  64          * Skip white space and pick up leading +/- sign if any.
  65          * If base is 0, allow 0x for hex and 0 for octal, else
  66          * assume decimal; if base is already 16, allow 0x.
  67          */
  68         s = nptr;
  69         do {
  70                 c = (unsigned char) *s++;
  71         } while (isspace(c));
  72         if (c == '-') {
  73                 neg = 1;
  74                 c = *s++;
  75         } else {
  76                 neg = 0;
  77                 if (c == '+')
  78                         c = *s++;
  79         }
  80         if ((base == 0 || base == 16) &&
  81             c == '0' && (*s == 'x' || *s == 'X')) {
  82                 c = s[1];
  83                 s += 2;
  84                 base = 16;
  85         }
  86         if (base == 0)
  87                 base = c == '0' ? 8 : 10;
  88
  89         /*
  90          * Compute the cutoff value between legal numbers and illegal
  91          * numbers.  That is the largest legal value, divided by the
  92          * base.  An input number that is greater than this value, if
  93          * followed by a legal input character, is too big.  One that
  94          * is equal to this value may be valid or not; the limit
  95          * between valid and invalid numbers is then based on the last
  96          * digit.  For instance, if the range for quads is
  97          * [-9223372036854775808..9223372036854775807] and the input base
  98          * is 10, cutoff will be set to 922337203685477580 and cutlim to
  99          * either 7 (neg==0) or 8 (neg==1), meaning that if we have
 100          * accumulated a value > 922337203685477580, or equal but the
 101          * next digit is > 7 (or 8), the number is too big, and we will
 102          * return a range error.
 103          *
 104          * Set any if any `digits' consumed; make it negative to indicate
 105          * overflow.
 106          */
 107         cutoff = neg ? QUAD_MIN : QUAD_MAX;
 108         cutlim = cutoff % base;
 109         cutoff /= base;
 110         if (neg) {
 111                 if (cutlim > 0) {
 112                         cutlim -= base;
 113                         cutoff += 1;
 114                 }
 115                 cutlim = -cutlim;
 116         }
 117         for (acc = 0, any = 0;; c = (unsigned char) *s++) {
 118                 if (isdigit(c))
 119                         c -= '0';
 120                 else if (isalpha(c))
 121                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 122                 else
 123                         break;
 124                 if (c >= base)
 125                         break;
 126                 if (any < 0)
 127                         continue;
 128                 if (neg) {
 129                         if (acc < cutoff || (acc == cutoff && c > cutlim)) {
 130                                 any = -1;
 131                                 acc = QUAD_MIN;
 132                                 __set_errno(ERANGE);
 133                         } else {
 134                                 any = 1;
 135                                 acc *= base;
 136                                 acc -= c;
 137                         }
 138                 } else {
 139                         if (acc > cutoff || (acc == cutoff && c > cutlim)) {
 140                                 any = -1;
 141                                 acc = QUAD_MAX;
 142                                 __set_errno(ERANGE);
 143                         } else {
 144                                 any = 1;
 145                                 acc *= base;
 146                                 acc += c;
 147                         }
 148                 }
 149         }
 150         if (endptr != 0)
 151                 *endptr = (char *) (any ? s - 1 : nptr);
 152         return (acc);
 153 }