xref: /freebsd/lib/libc/stdio/fgetwc.c (revision 7c43148a974877188a930e4078a164f83da8e652)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2002-2004 Tim J. Robbins.
5  * All rights reserved.
6  *
7  * Copyright (c) 2011 The FreeBSD Foundation
8  *
9  * Portions of this software were developed by David Chisnall
10  * under sponsorship from the FreeBSD Foundation.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "namespace.h"
35 #include <errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <wchar.h>
39 #include "un-namespace.h"
40 #include "libc_private.h"
41 #include "local.h"
42 #include "mblocal.h"
43 #include "xlocale_private.h"
44 
45 /*
46  * MT-safe version.
47  */
48 wint_t
49 fgetwc_l(FILE *fp, locale_t locale)
50 {
51 	wint_t r;
52 	FIX_LOCALE(locale);
53 
54 	FLOCKFILE_CANCELSAFE(fp);
55 	ORIENT(fp, 1);
56 	r = __fgetwc(fp, locale);
57 	FUNLOCKFILE_CANCELSAFE();
58 
59 	return (r);
60 }
61 
62 wint_t
63 fgetwc(FILE *fp)
64 {
65 	return fgetwc_l(fp, __get_locale());
66 }
67 
68 /*
69  * Internal (non-MPSAFE) version of fgetwc().  This version takes an
70  * mbstate_t argument specifying the initial conversion state.  For
71  * wide streams, this should always be fp->_mbstate.  On return, *nread
72  * is set to the number of bytes read.
73  */
74 wint_t
75 __fgetwc_mbs(FILE *fp, mbstate_t *mbs, int *nread, locale_t locale)
76 {
77 	wchar_t wc;
78 	size_t nconv;
79 	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
80 
81 	*nread = 0;
82 	if (fp->_r <= 0 && __srefill(fp))
83 		return (WEOF);
84 	do {
85 		nconv = l->__mbrtowc(&wc, fp->_p, fp->_r, mbs);
86 		if (nconv == (size_t)-1) {
87 			fp->_flags |= __SERR;
88 			return (WEOF);
89 		} else if (nconv == (size_t)-2)
90 			continue;
91 		else if (nconv == 0) {
92 			fp->_p++;
93 			fp->_r--;
94 			(*nread)++;
95 			return (L'\0');
96 		} else {
97 			fp->_p += nconv;
98 			fp->_r -= nconv;
99 			*nread += nconv;
100 			return (wc);
101 		}
102 	} while (__srefill(fp) == 0);
103 	if (__sfeof(fp)) {
104 		fp->_flags |= __SERR;
105 		errno = EILSEQ;
106 	}
107 	return (WEOF);
108 }
109