1/*	$NetBSD: strtol.c,v 1.2 2009/03/14 15:36:08 dsl 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. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37
38#if defined(LIBC_SCCS) && !defined(lint)
39static char sccsid[] = "@(#)strtol.c	8.1 (Berkeley) 6/4/93";
40#endif /* LIBC_SCCS and not lint */
41
42#include <lib/libsa/stand.h>
43#include <lib/libsa/loadfile.h>
44#include <lib/libkern/libkern.h>
45
46#include <machine/limits.h>
47
48#include "bootstrap.h"
49
50/*
51 * Convert a string to a long integer.
52 *
53 * Ignores `locale' stuff.  Assumes that the upper and lower case
54 * alphabets and digits are each contiguous.
55 */
56long
57strtol(const char *nptr, char **endptr, int base)
58{
59	const char *s;
60	unsigned long acc;
61	unsigned char c;
62	unsigned long cutoff;
63	int neg = 0, any, cutlim;
64
65	/* Be sensible about NULL strings */
66	if (nptr == NULL)
67	    nptr = "";
68	s = nptr;
69
70	/*
71	 * Skip white space and pick up leading +/- sign if any.
72	 * If base is 0, allow 0x for hex and 0 for octal, else
73	 * assume decimal; if base is already 16, allow 0x.
74	 */
75	do {
76		c = *s++;
77	} while (isspace(c));
78	if (c == '-') {
79		neg = 1;
80		c = *s++;
81	} else if (c == '+')
82		c = *s++;
83	if ((base == 0 || base == 16) &&
84	    c == '0' && (*s == 'x' || *s == 'X')) {
85		c = s[1];
86		s += 2;
87		base = 16;
88	}
89	if (base == 0)
90		base = c == '0' ? 8 : 10;
91
92	/*
93	 * Compute the cutoff value between legal numbers and illegal
94	 * numbers.  That is the largest legal value, divided by the
95	 * base.  An input number that is greater than this value, if
96	 * followed by a legal input character, is too big.  One that
97	 * is equal to this value may be valid or not; the limit
98	 * between valid and invalid numbers is then based on the last
99	 * digit.  For instance, if the range for longs is
100	 * [-2147483648..2147483647] and the input base is 10,
101	 * cutoff will be set to 214748364 and cutlim to either
102	 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
103	 * a value > 214748364, or equal but the next digit is > 7 (or 8),
104	 * the number is too big, and we will return a range error.
105	 *
106	 * Set any if any `digits' consumed; make it negative to indicate
107	 * overflow.
108	 */
109	cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
110	cutlim = cutoff % (unsigned long)base;
111	cutoff /= (unsigned long)base;
112	for (acc = 0, any = 0;; c = *s++) {
113		if (!isascii(c))
114			break;
115		if (isdigit(c))
116			c -= '0';
117		else if (isalpha(c))
118			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
119		else
120			break;
121		if (c >= base)
122			break;
123		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
124			any = -1;
125		else {
126			any = 1;
127			acc *= base;
128			acc += c;
129		}
130	}
131	if (any < 0) {
132		acc = neg ? LONG_MIN : LONG_MAX;
133		errno = ERANGE;
134	} else if (neg)
135		acc = -acc;
136	if (endptr != 0)
137		*endptr = (char *)(any ? s - 1 : nptr);
138	return (acc);
139}
140