StdLib/LibC/StdLib/strtoumax.c

   1 /*  $NetBSD: strtoumax.c,v 1.1 2006/04/22 15:33:33 thorpej Exp $  */
   2
   3 /*
   4  * Copyright (c) 1990, 1993
   5  *  The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31 #include  <LibConfig.h>
  32 #include <sys/EfiCdefs.h>
  33
  34 #if !defined(_KERNEL) && !defined(_STANDALONE)
  35 #if defined(LIBC_SCCS) && !defined(lint)
  36 #if 0
  37 static char sccsid[] = "from: @(#)strtoul.c 8.1 (Berkeley) 6/4/93";
  38 #else
  39 __RCSID("$NetBSD: strtoumax.c,v 1.1 2006/04/22 15:33:33 thorpej Exp $");
  40 #endif
  41 #endif /* LIBC_SCCS and not lint */
  42
  43 #include "namespace.h"
  44
  45 #include <assert.h>
  46 #include <ctype.h>
  47 #include <errno.h>
  48 #include <inttypes.h>
  49 #include <stddef.h>
  50
  51 #ifdef __weak_alias
  52 __weak_alias(strtoumax, _strtoumax)
  53 #endif
  54
  55 #else /* !_KERNEL && !_STANDALONE */
  56 #include <sys/param.h>
  57 #include <lib/libkern/libkern.h>
  58 #endif /* !_KERNEL && !_STANDALONE */
  59
  60 /*
  61  * Convert a string to an uintmax_t.
  62  *
  63  * Ignores `locale' stuff.  Assumes that the upper and lower case
  64  * alphabets and digits are each contiguous.
  65  */
  66 uintmax_t
  67 strtoumax(const char *nptr, char **endptr, int base)
  68 {
  69   const char *s;
  70   uintmax_t acc, cutoff;
  71   int c;
  72   int neg, any, cutlim;
  73
  74   _DIAGASSERT(nptr != NULL);
  75   /* endptr may be NULL */
  76
  77   /*
  78    * See strtol for comments as to the logic used.
  79    */
  80   s = nptr;
  81   do {
  82     c = (unsigned char) *s++;
  83   } while (isspace(c));
  84   if (c == '-') {
  85     neg = 1;
  86     c = *s++;
  87   } else {
  88     neg = 0;
  89     if (c == '+')
  90       c = *s++;
  91   }
  92   if ((base == 0 || base == 16) &&
  93       c == '0' && (*s == 'x' || *s == 'X')) {
  94     c = s[1];
  95     s += 2;
  96     base = 16;
  97   }
  98   if (base == 0)
  99     base = c == '0' ? 8 : 10;
 100
 101   cutoff = UINTMAX_MAX / (uintmax_t)base;
 102   cutlim = (int)(UINTMAX_MAX % (uintmax_t)base);
 103   for (acc = 0, any = 0;; c = (unsigned char) *s++) {
 104     if (isdigit(c))
 105       c -= '0';
 106     else if (isalpha(c)) {
 107 #if defined(_KERNEL) || defined(_STANDALONE)
 108       c = toupper(c) - 'A' + 10;
 109 #else
 110       c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 111 #endif
 112     } else
 113       break;
 114     if (c >= base)
 115       break;
 116     if (any < 0)
 117       continue;
 118     if (acc > cutoff || (acc == cutoff && c > cutlim)) {
 119 #if defined(_KERNEL) || defined(_STANDALONE)
 120       if (endptr)
 121         *endptr = __UNCONST(nptr);
 122       return UINTMAX_MAX;
 123 #else
 124       any = -1;
 125       acc = UINTMAX_MAX;
 126       errno = ERANGE;
 127 #endif
 128     } else {
 129       any = 1;
 130       acc *= (uintmax_t)base;
 131       acc += c;
 132     }
 133   }
 134   if (neg && any > 0)
 135     acc = (uintmax_t)(-((intmax_t)acc));
 136   if (endptr != 0)
 137     *endptr = __UNCONST(any ? s - 1 : nptr);
 138   return (acc);
 139 }