vx32

Local 9vx git repository for patches.
git clone git://r-36.net/vx32
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strtol.c (4415B)


      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. 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 <limits.h>
     35 #include <ctype.h>
     36 #include <errno.h>
     37 #include <stdlib.h>
     38 
     39 
     40 /*
     41  * Convert a string to a long integer.
     42  *
     43  * Assumes that the upper and lower case
     44  * alphabets and digits are each contiguous.
     45  */
     46 long
     47 strtol(const char * __restrict nptr, char ** __restrict endptr, int base)
     48 {
     49 	const char *s;
     50 	unsigned long acc;
     51 	char c;
     52 	unsigned long cutoff;
     53 	int neg, any, cutlim;
     54 
     55 	/*
     56 	 * Skip white space and pick up leading +/- sign if any.
     57 	 * If base is 0, allow 0x for hex and 0 for octal, else
     58 	 * assume decimal; if base is already 16, allow 0x.
     59 	 */
     60 	s = nptr;
     61 	do {
     62 		c = *s++;
     63 	} while (isspace((unsigned char)c));
     64 	if (c == '-') {
     65 		neg = 1;
     66 		c = *s++;
     67 	} else {
     68 		neg = 0;
     69 		if (c == '+')
     70 			c = *s++;
     71 	}
     72 	if ((base == 0 || base == 16) &&
     73 	    c == '0' && (*s == 'x' || *s == 'X') &&
     74 	    ((s[1] >= '0' && s[1] <= '9') ||
     75 	    (s[1] >= 'A' && s[1] <= 'F') ||
     76 	    (s[1] >= 'a' && s[1] <= 'f'))) {
     77 		c = s[1];
     78 		s += 2;
     79 		base = 16;
     80 	}
     81 	if (base == 0)
     82 		base = c == '0' ? 8 : 10;
     83 	acc = any = 0;
     84 	if (base < 2 || base > 36)
     85 		goto noconv;
     86 
     87 	/*
     88 	 * Compute the cutoff value between legal numbers and illegal
     89 	 * numbers.  That is the largest legal value, divided by the
     90 	 * base.  An input number that is greater than this value, if
     91 	 * followed by a legal input character, is too big.  One that
     92 	 * is equal to this value may be valid or not; the limit
     93 	 * between valid and invalid numbers is then based on the last
     94 	 * digit.  For instance, if the range for longs is
     95 	 * [-2147483648..2147483647] and the input base is 10,
     96 	 * cutoff will be set to 214748364 and cutlim to either
     97 	 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
     98 	 * a value > 214748364, or equal but the next digit is > 7 (or 8),
     99 	 * the number is too big, and we will return a range error.
    100 	 *
    101 	 * Set 'any' if any `digits' consumed; make it negative to indicate
    102 	 * overflow.
    103 	 */
    104 	cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX
    105 	    : LONG_MAX;
    106 	cutlim = cutoff % base;
    107 	cutoff /= base;
    108 	for ( ; ; c = *s++) {
    109 		if (c >= '0' && c <= '9')
    110 			c -= '0';
    111 		else if (c >= 'A' && c <= 'Z')
    112 			c -= 'A' - 10;
    113 		else if (c >= 'a' && c <= 'z')
    114 			c -= 'a' - 10;
    115 		else
    116 			break;
    117 		if (c >= base)
    118 			break;
    119 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
    120 			any = -1;
    121 		else {
    122 			any = 1;
    123 			acc *= base;
    124 			acc += c;
    125 		}
    126 	}
    127 	if (any < 0) {
    128 		acc = neg ? LONG_MIN : LONG_MAX;
    129 		errno = ERANGE;
    130 	} else if (!any) {
    131 noconv:
    132 		errno = EINVAL;
    133 	} else if (neg)
    134 		acc = -acc;
    135 	if (endptr != NULL)
    136 		*endptr = (char *)(any ? s - 1 : nptr);
    137 	return (acc);
    138 }