1/*-
2 * SPDX-License-Identifier: MIT
3 *
4 * Copyright (c) 2005-2014 Rich Felker, et al.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining
7 * a copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sublicense, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be
15 * included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
21 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
22 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
23 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 */
25#include <limits.h>
26#include <stdint.h>
27#include <string.h>
28
29#define ALIGN (sizeof(size_t))
30#define ONES ((size_t)-1 / UCHAR_MAX)
31#define HIGHS (ONES * (UCHAR_MAX / 2 + 1))
32#define HASZERO(x) (((x)-ONES) & ~(x)&HIGHS)
33
34char *__strchrnul(const char *, int);
35
36char *
37__strchrnul(const char *s, int c)
38{
39	c = (unsigned char)c;
40	if (!c)
41		return (char *)s + strlen(s);
42
43#ifdef __GNUC__
44	typedef size_t __attribute__((__may_alias__)) word;
45	const word *w;
46	for (; (uintptr_t)s % ALIGN; s++)
47		if (!*s || *(unsigned char *)s == c)
48			return (char *)s;
49	size_t k = ONES * c;
50	for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w ^ k); w++)
51		;
52	s = (void *)w;
53#endif
54	for (; *s && *(unsigned char *)s != c; s++)
55		;
56	return (char *)s;
57}
58
59__weak_reference(__strchrnul, strchrnul);
60