_strtoul.h revision 331722 
1/* $FreeBSD: stable/11/lib/libc/iconv/_strtoul.h 331722 2018-03-29 02:50:57Z eadler $ */
2/* $NetBSD: _strtoul.h,v 1.1 2008/08/20 12:42:26 joerg Exp $ */
3
4/*-
5 * Copyright (c) 1990, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * Original version ID:
33 * NetBSD: src/lib/libc/locale/_wcstoul.h,v 1.2 2003/08/07 16:43:03 agc Exp
34 */
35
36/*
37 * function template for strtoul, strtoull and strtoumax.
38 *
39 * parameters:
40 *	_FUNCNAME  : function name
41 *      __UINT     : return type
42 *      __UINT_MAX : upper limit of the return type
43 */
44
45__UINT
46_FUNCNAME(const char *nptr, char **endptr, int base)
47{
48	const char *s;
49	__UINT acc, cutoff;
50	unsigned char c;
51	int any, cutlim, i, neg;
52
53	/* check base value */
54	if (base && (base < 2 || base > 36)) {
55#if !defined(_KERNEL) && !defined(_STANDALONE)
56		errno = EINVAL;
57		return (0);
58#else
59		panic("%s: invalid base %d", __func__, base);
60#endif
61	}
62
63	/*
64	 * Skip white space and pick up leading +/- sign if any.
65	 * If base is 0, allow 0x for hex and 0 for octal, else
66	 * assume decimal; if base is already 16, allow 0x.
67	 */
68	s = nptr;
69	do {
70		c = *s++;
71	} while (isspace(c));
72	if (c == '-') {
73		neg = 1;
74		c = *s++;
75	} else {
76		neg = 0;
77		if (c == '+')
78			c = *s++;
79	}
80	if ((base == 0 || base == 16) &&
81	    c == '0' && (*s == 'x' || *s == 'X')) {
82		c = s[1];
83		s += 2;
84		base = 16;
85	}
86	if (base == 0)
87		base = (c == '0' ? 8 : 10);
88
89	/*
90	 * See strtol for comments as to the logic used.
91	 */
92	cutoff = __UINT_MAX / (__UINT)base;
93	cutlim = (int)(__UINT_MAX % (__UINT)base);
94	for (acc = 0, any = 0;; c = *s++) {
95		if (isdigit(c))
96			i = c - '0';
97		else if (isalpha(c))
98			i = c - (isupper(c) ? 'A' - 10 : 'a' - 10);
99		else
100			break;
101		if (i >= base)
102			break;
103		if (any < 0)
104			continue;
105		if (acc > cutoff || (acc == cutoff && i > cutlim)) {
106			acc = __UINT_MAX;
107#if !defined(_KERNEL) && !defined(_STANDALONE)
108			any = -1;
109			errno = ERANGE;
110#else
111			any = 0;
112			break;
113#endif
114		} else {
115			any = 1;
116			acc *= (__UINT)base;
117			acc += i;
118		}
119	}
120	if (neg && any > 0)
121		acc = -acc;
122	if (endptr != NULL)
123		/* LINTED interface specification */
124		*endptr = __DECONST(void *, any ? s - 1 : nptr);
125	return (acc);
126}
127