xref: /freebsd/contrib/llvm-project/llvm/lib/Support/regstrlcpy.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*
2  * This code is derived from OpenBSD's libc, original license follows:
3  *
4  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <string.h>
21 
22 #include "regex_impl.h"
23 /*
24  * Copy src to string dst of size siz.  At most siz-1 characters
25  * will be copied.  Always NUL terminates (unless siz == 0).
26  * Returns strlen(src); if retval >= siz, truncation occurred.
27  */
28 size_t
29 llvm_strlcpy(char *dst, const char *src, size_t siz)
30 {
31 	char *d = dst;
32 	const char *s = src;
33 	size_t n = siz;
34 
35 	/* Copy as many bytes as will fit */
36 	if (n != 0) {
37 		while (--n != 0) {
38 			if ((*d++ = *s++) == '\0')
39 				break;
40 		}
41 	}
42 
43 	/* Not enough room in dst, add NUL and traverse rest of src */
44 	if (n == 0) {
45 		if (siz != 0)
46 			*d = '\0';		/* NUL-terminate dst */
47 		while (*s++)
48 			;
49 	}
50 
51 	return(s - src - 1);	/* count does not include NUL */
52 }
53