xref: /freebsd/lib/libc/locale/wcsrtombs.c (revision ea4ac135ff6e5e1881e3ebe0e730bcf1223cfbe7)
1 /*-
2  * Copyright (c) 2002-2004 Tim J. Robbins.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <limits.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <wchar.h>
34 #include "mblocal.h"
35 
36 size_t
37 wcsrtombs(char * __restrict dst, const wchar_t ** __restrict src, size_t len,
38     mbstate_t * __restrict ps)
39 {
40 	static mbstate_t mbs;
41 
42 	if (ps == NULL)
43 		ps = &mbs;
44 	return (__wcsrtombs(dst, src, len, ps));
45 }
46 
47 size_t
48 __wcsrtombs_std(char * __restrict dst, const wchar_t ** __restrict src,
49     size_t len, mbstate_t * __restrict ps)
50 {
51 	mbstate_t mbsbak;
52 	char buf[MB_LEN_MAX];
53 	const wchar_t *s;
54 	size_t nbytes;
55 	int nb;
56 
57 	s = *src;
58 	nbytes = 0;
59 
60 	if (dst == NULL) {
61 		for (;;) {
62 			if ((nb = (int)__wcrtomb(buf, *s, ps)) < 0)
63 				/* Invalid character - wcrtomb() sets errno. */
64 				return ((size_t)-1);
65 			else if (*s == L'\0')
66 				return (nbytes + nb - 1);
67 			s++;
68 			nbytes += nb;
69 		}
70 		/*NOTREACHED*/
71 	}
72 
73 	while (len > 0) {
74 		if (len > (size_t)MB_CUR_MAX) {
75 			/* Enough space to translate in-place. */
76 			if ((nb = (int)__wcrtomb(dst, *s, ps)) < 0) {
77 				*src = s;
78 				return ((size_t)-1);
79 			}
80 		} else {
81 			/*
82 			 * May not be enough space; use temp. buffer.
83 			 *
84 			 * We need to save a copy of the conversion state
85 			 * here so we can restore it if the multibyte
86 			 * character is too long for the buffer.
87 			 */
88 			mbsbak = *ps;
89 			if ((nb = (int)__wcrtomb(buf, *s, ps)) < 0) {
90 				*src = s;
91 				return ((size_t)-1);
92 			}
93 			if (nb > (int)len) {
94 				/* MB sequence for character won't fit. */
95 				*ps = mbsbak;
96 				break;
97 			}
98 			memcpy(dst, buf, nb);
99 		}
100 		if (*s == L'\0') {
101 			*src = NULL;
102 			return (nbytes + nb - 1);
103 		}
104 		s++;
105 		dst += nb;
106 		len -= nb;
107 		nbytes += nb;
108 	}
109 	*src = s;
110 	return (nbytes);
111 }
112