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 <sys/cdefs.h>
26 #include <limits.h>
27 #include <stdint.h>
28 #include <string.h>
29
30 #define ALIGN (sizeof(size_t))
31 #define ONES ((size_t)-1 / UCHAR_MAX)
32 #define HIGHS (ONES * (UCHAR_MAX / 2 + 1))
33 #define HASZERO(x) (((x)-ONES) & ~(x)&HIGHS)
34
35 char *__strchrnul(const char *, int);
36
37 char *
__strchrnul(const char * s,int c)38 __strchrnul(const char *s, int c)
39 {
40 c = (unsigned char)c;
41 if (!c)
42 return (char *)s + strlen(s);
43
44 #ifdef __GNUC__
45 typedef size_t __attribute__((__may_alias__)) word;
46 const word *w;
47 for (; (uintptr_t)s % ALIGN; s++)
48 if (!*s || *(unsigned char *)s == c)
49 return (char *)s;
50 size_t k = ONES * c;
51 for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w ^ k); w++)
52 ;
53 s = (void *)w;
54 #endif
55 for (; *s && *(unsigned char *)s != c; s++)
56 ;
57 return (char *)s;
58 }
59
60 __weak_reference(__strchrnul, strchrnul);
61