newlib/libc/stdlib/strtoimax.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  * 3. 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 #if defined(LIBC_SCCS) && !defined(lint)
  36 static char sccsid[] = "from @(#)strtol.c       8.1 (Berkeley) 6/4/93";
  37 #endif /* LIBC_SCCS and not lint */
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD: head/lib/libc/stdlib/strtoimax.c 251672 2013-06-13 00:19:30Z emaste $");
  40
  41 #include <ctype.h>
  42 #include <errno.h>
  43 #include <stdlib.h>
  44 #include <inttypes.h>
  45 #include <stdint.h>
  46 #include <reent.h>
  47 #include "../locale/setlocale.h"
  48
  49 /*
  50  * Convert a string to an intmax_t integer.
  51  *
  52  * Assumes that the upper and lower case
  53  * alphabets and digits are each contiguous.
  54  */
  55
  56 /*
  57  *Reentrant version of strtoimax.
  58  */
  59 static intmax_t
  60 _strtoimax_l(struct _reent *rptr, const char * __restrict nptr,
  61              char ** __restrict endptr, int base, locale_t loc)
  62 {
  63         const char *s = nptr;
  64         uintmax_t acc = 0;
  65         char c;
  66         uintmax_t cutoff;
  67         int neg = 0, any = 0, cutlim;
  68
  69         /*
  70          * Skip white space and pick up leading +/- sign if any.
  71          * If base is 0, allow 0x for hex and 0 for octal, else
  72          * assume decimal; if base is already 16, allow 0x.
  73          */
  74         do {
  75                 c = *s++;
  76         } while (isspace_l(c, loc));
  77         if (c == '-') {
  78                 neg = 1;
  79                 c = *s++;
  80         } else {
  81                 neg = 0;
  82                 if (c == '+')
  83                         c = *s++;
  84         }
  85         if ((base == 0 || base == 16) &&
  86             c == '0' && (*s == 'x' || *s == 'X')) {
  87                 c = s[1];
  88                 s += 2;
  89                 base = 16;
  90         }
  91         if (base == 0)
  92                 base = c == '0' ? 8 : 10;
  93
  94         if (base < 2 || base > 36)
  95                 goto noconv;
  96
  97         /*
  98          * Compute the cutoff value between legal numbers and illegal
  99          * numbers.  That is the largest legal value, divided by the
 100          * base.  An input number that is greater than this value, if
 101          * followed by a legal input character, is too big.  One that
 102          * is equal to this value may be valid or not; the limit
 103          * between valid and invalid numbers is then based on the last
 104          * digit.  For instance, if the range for intmax_t is
 105          * [-9223372036854775808..9223372036854775807] and the input base
 106          * is 10, cutoff will be set to 922337203685477580 and cutlim to
 107          * either 7 (neg==0) or 8 (neg==1), meaning that if we have
 108          * accumulated a value > 922337203685477580, or equal but the
 109          * next digit is > 7 (or 8), the number is too big, and we will
 110          * return a range error.
 111          *
 112          * Set 'any' if any `digits' consumed; make it negative to indicate
 113          * overflow.
 114          */
 115         cutoff = neg ? -(uintmax_t)INTMAX_MIN : INTMAX_MAX;
 116         cutlim = cutoff % base;
 117         cutoff /= base;
 118         for ( ; ; c = *s++) {
 119                 if (c >= '0' && c <= '9')
 120                         c -= '0';
 121                 else if (c >= 'A' && c <= 'Z')
 122                         c -= 'A' - 10;
 123                 else if (c >= 'a' && c <= 'z')
 124                         c -= 'a' - 10;
 125                 else
 126                         break;
 127                 if (c >= base)
 128                         break;
 129                 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 130                         any = -1;
 131                 else {
 132                         any = 1;
 133                         acc *= base;
 134                         acc += c;
 135                 }
 136         }
 137         if (any < 0) {
 138                 acc = neg ? INTMAX_MIN : INTMAX_MAX;
 139                 _REENT_ERRNO(rptr) = ERANGE;
 140         } else if (!any) {
 141 noconv:
 142                 _REENT_ERRNO(rptr) = EINVAL;
 143         } else if (neg)
 144                 acc = -acc;
 145         if (endptr != NULL)
 146                 *endptr = (char *)(any ? s - 1 : nptr);
 147         return (acc);
 148 }
 149
 150 intmax_t
 151 _strtoimax_r(struct _reent *rptr, const char *__restrict nptr,
 152              char **__restrict endptr, int base)
 153 {
 154         return _strtoimax_l(rptr, nptr, endptr, base, __get_current_locale());
 155 }
 156
 157 #ifndef _REENT_ONLY
 158
 159 intmax_t
 160 strtoimax_l(const char * __restrict nptr, char ** __restrict endptr, int base,
 161             locale_t loc)
 162 {
 163         return _strtoimax_l(_REENT, nptr, endptr, base, loc);
 164 }
 165
 166 intmax_t
 167 strtoimax(const char* __restrict nptr, char** __restrict endptr, int base)
 168 {
 169         return _strtoimax_l(_REENT, nptr, endptr, base, __get_current_locale());
 170 }
 171
 172 #endif