lib/libc/citrus/_strtol.h

   1 /* $FreeBSD: head/lib/libc/iconv/_strtol.h 219019 2011-02-25 00:04:39Z gabor $ */
   2 /* $NetBSD: _strtol.h,v 1.2 2009/05/20 22:03:29 christos Exp $ */
   3
   4 /*-
   5  * Copyright (c) 1990, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * Original version ID:
  33  * NetBSD: src/lib/libc/locale/_wcstol.h,v 1.2 2003/08/07 16:43:03 agc Exp
  34  */
  35
  36 /*
  37  * function template for strtol, strtoll and strtoimax.
  38  *
  39  * parameters:
  40  *      _FUNCNAME : function name
  41  *      __INT     : return type
  42  *      INT_MIN : lower limit of the return type
  43  *      INT_MAX : upper limit of the return type
  44  */
  45
  46 __INT
  47 _FUNCNAME(const char *nptr, char **endptr, int base)
  48 {
  49         const char *s;
  50         __INT acc, cutoff;
  51         unsigned char c;
  52         int any, cutlim, i, neg;
  53
  54         /* check base value */
  55         if (base && (base < 2 || base > 36)) {
  56 #if !defined(_KERNEL) && !defined(_STANDALONE)
  57                 errno = EINVAL;
  58                 if (endptr != NULL)
  59                         /* LINTED interface specification */
  60                         *endptr = __DECONST(void *, nptr);
  61                 return (0);
  62 #else
  63                 panic("%s: invalid base %d", __func__, base);
  64 #endif
  65         }
  66
  67         /*
  68          * Skip white space and pick up leading +/- sign if any.
  69          * If base is 0, allow 0x for hex and 0 for octal, else
  70          * assume decimal; if base is already 16, allow 0x.
  71          */
  72         s = nptr;
  73         do {
  74                 c = *s++;
  75         } while (isspace(c));
  76         if (c == '-') {
  77                 neg = 1;
  78                 c = *s++;
  79         } else {
  80                 neg = 0;
  81                 if (c == '+')
  82                         c = *s++;
  83         }
  84         if ((base == 0 || base == 16) &&
  85             c == '0' && (*s == 'x' || *s == 'X')) {
  86                 c = s[1];
  87                 s += 2;
  88                 base = 16;
  89         }
  90         if (base == 0)
  91                 base = (c == '0' ? 8 : 10);
  92
  93         /*
  94          * Compute the cutoff value between legal numbers and illegal
  95          * numbers.  That is the largest legal value, divided by the
  96          * base.  An input number that is greater than this value, if
  97          * followed by a legal input character, is too big.  One that
  98          * is equal to this value may be valid or not; the limit
  99          * between valid and invalid numbers is then based on the last
 100          * digit.  For instance, if the range for longs is
 101          * [-2147483648..2147483647] and the input base is 10,
 102          * cutoff will be set to 214748364 and cutlim to either
 103          * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 104          * a value > 214748364, or equal but the next digit is > 7 (or 8),
 105          * the number is too big, and we will return a range error.
 106          *
 107          * Set any if any `digits' consumed; make it negative to indicate
 108          * overflow.
 109          */
 110         cutoff = (neg ? INT_MIN : INT_MAX);
 111         cutlim = (int)(cutoff % base);
 112         cutoff /= base;
 113         if (neg) {
 114                 if (cutlim > 0) {
 115                         cutlim -= base;
 116                         cutoff += 1;
 117                 }
 118                 cutlim = -cutlim;
 119         }
 120         for (acc = 0, any = 0;; c = *s++) {
 121                 if (isdigit(c))
 122                         i = c - '0';
 123                 else if (isalpha(c))
 124                         i = c - (isupper(c) ? 'A' - 10 : 'a' - 10);
 125                 else
 126                         break;
 127                 if (i >= base)
 128                         break;
 129                 if (any < 0)
 130                         continue;
 131                 if (neg) {
 132                         if (acc < cutoff || (acc == cutoff && i > cutlim)) {
 133                                 acc = INT_MIN;
 134 #if !defined(_KERNEL) && !defined(_STANDALONE)
 135                                 any = -1;
 136                                 errno = ERANGE;
 137 #else
 138                                 any = 0;
 139                                 break;
 140 #endif
 141                         } else {
 142                                 any = 1;
 143                                 acc *= base;
 144                                 acc -= i;
 145                         }
 146                 } else {
 147                         if (acc > cutoff || (acc == cutoff && i > cutlim)) {
 148                                 acc = INT_MAX;
 149 #if !defined(_KERNEL) && !defined(_STANDALONE)
 150                                 any = -1;
 151                                 errno = ERANGE;
 152 #else
 153                                 any = 0;
 154                                 break;
 155 #endif
 156                         } else {
 157                                 any = 1;
 158                                 acc *= base;
 159                                 acc += i;
 160                         }
 161                 }
 162         }
 163         if (endptr != NULL)
 164                 /* LINTED interface specification */
 165                 *endptr = __DECONST(void *, any ? s - 1 : nptr);
 166         return(acc);
 167 }