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   * 4. 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  
 30  #if defined(LIBC_SCCS) && !defined(lint)
 31  static char sccsid[] = "@(#)strtol.c	8.1 (Berkeley) 6/4/93";
 32  #endif /* LIBC_SCCS and not lint */
 33  #include <sys/cdefs.h>
 34  __FBSDID("$FreeBSD: src/lib/libc/stdlib/strtol.c,v 1.20 2007/01/09 00:28:10 imp Exp $");
 35  
 36  #include "xlocale_private.h"
 37  
 38  #include <limits.h>
 39  #include <ctype.h>
 40  #include <errno.h>
 41  #include <stdlib.h>
 42  
 43  
 44  /*
 45   * Convert a string to a long integer.
 46   *
 47   * Assumes that the upper and lower case
 48   * alphabets and digits are each contiguous.
 49   */
 50  long
 51  strtol_l(const char * __restrict nptr, char ** __restrict endptr, int base,
 52      locale_t loc)
 53  {
 54  	const char *s;
 55  	unsigned long acc;
 56  	char c;
 57  	unsigned long cutoff;
 58  	int neg, any, cutlim;
 59  
 60  	NORMALIZE_LOCALE(loc);
 61  	/*
 62  	 * Skip white space and pick up leading +/- sign if any.
 63  	 * If base is 0, allow 0x for hex and 0 for octal, else
 64  	 * assume decimal; if base is already 16, allow 0x.
 65  	 */
 66  	s = nptr;
 67  	do {
 68  		c = *s++;
 69  	} while (isspace_l((unsigned char)c, loc));
 70  	if (c == '-') {
 71  		neg = 1;
 72  		c = *s++;
 73  	} else {
 74  		neg = 0;
 75  		if (c == '+')
 76  			c = *s++;
 77  	}
 78  	if ((base == 0 || base == 16) &&
 79  	    c == '0' && (*s == 'x' || *s == 'X') &&
 80  	    ((s[1] >= '0' && s[1] <= '9') ||
 81  	    (s[1] >= 'A' && s[1] <= 'F') ||
 82  	    (s[1] >= 'a' && s[1] <= 'f'))) {
 83  		c = s[1];
 84  		s += 2;
 85  		base = 16;
 86  	}
 87  	if (base == 0)
 88  		base = c == '0' ? 8 : 10;
 89  	acc = any = 0;
 90  	if (base < 2 || base > 36)
 91  		goto noconv;
 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 ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX
111  	    : LONG_MAX;
112  	cutlim = cutoff % base;
113  	cutoff /= base;
114  	for ( ; ; c = *s++) {
115  		if (c >= '0' && c <= '9')
116  			c -= '0';
117  		else if (c >= 'A' && c <= 'Z')
118  			c -= 'A' - 10;
119  		else if (c >= 'a' && c <= 'z')
120  			c -= 'a' - 10;
121  		else
122  			break;
123  		if (c >= base)
124  			break;
125  		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
126  			any = -1;
127  		else {
128  			any = 1;
129  			acc *= base;
130  			acc += c;
131  		}
132  	}
133  	if (any < 0) {
134  		acc = neg ? LONG_MIN : LONG_MAX;
135  		errno = ERANGE;
136  	} else if (!any) {
137  noconv:
138  		errno = EINVAL;
139  	} else if (neg)
140  		acc = -acc;
141  	if (endptr != NULL)
142  		*endptr = (char *)(any ? s - 1 : nptr);
143  	return (acc);
144  }
145  
146  long
147  strtol(const char * __restrict nptr, char ** __restrict endptr, int base)
148  {
149  	return strtol_l(nptr, endptr, base, __current_locale());
150  }