lib/libc/stdlib/_strtol.h

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