xref: /illumos-gate/usr/src/lib/libc/port/locale/fgetwc.c (revision f3041bfa)
1 /*
2  * Copyright 2013 Garrett D'Amore <garrett@damore.org>
3  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
4  * Copyright (c) 2002-2004 Tim J. Robbins.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include "lint.h"
30 #include "mse_int.h"
31 #include "file64.h"
32 #include "mtlib.h"
33 #include <errno.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <wchar.h>
37 #include "mblocal.h"
38 #include "stdiom.h"
39 #include "localeimpl.h"
40 #include "lctype.h"
41 
42 /*
43  * Non-MT-safe version.
44  */
45 wint_t
46 _fgetwc_unlocked_l(FILE *fp, locale_t loc)
47 {
48 	wchar_t wc;
49 	size_t nconv;
50 	int	c;
51 	mbstate_t	*statep;
52 	const struct lc_ctype *lct;
53 
54 	if ((c = GETC(fp)) == EOF)
55 		return (WEOF);
56 
57 	lct = loc->ctype;
58 	if (lct->lc_max_mblen == 1) {
59 		/* Fast path for single-byte encodings. */
60 		return ((wint_t)c);
61 	}
62 	if ((statep = _getmbstate(fp)) == NULL) {
63 		fp->_flag = _IOERR;
64 		errno = EBADF;
65 		return (WEOF);
66 	}
67 	do {
68 		char	x = (char)c;
69 		nconv = lct->lc_mbrtowc(&wc, &x, 1, statep);
70 		if (nconv == (size_t)-1) {
71 			break;
72 		} else if (nconv == (size_t)-2) {
73 			/* Incompletely decoded, consume another char */
74 			continue;
75 		} else if (nconv == 0) {
76 			/*
77 			 * Assume that the only valid representation of
78 			 * the null wide character is a single null byte.
79 			 */
80 			return (L'\0');
81 		} else {
82 			return (wc);
83 		}
84 	} while ((c = GETC(fp)) != EOF);
85 
86 	/*
87 	 * If we got here it means we got truncated in a character, or
88 	 * the character did not decode properly.  Note that in the case
89 	 * of a botched decoding, we don't UNGETC the bad bytes.  Should
90 	 * we?
91 	 */
92 	fp->_flag |= _IOERR;
93 	errno = EILSEQ;
94 	return (WEOF);
95 }
96 
97 wint_t
98 _fgetwc_unlocked(FILE *fp)
99 {
100 	return (_fgetwc_unlocked_l(fp, uselocale(NULL)));
101 }
102 
103 
104 /*
105  * MT safe version
106  */
107 #undef getwc
108 #pragma weak getwc = fgetwc
109 wint_t
110 fgetwc(FILE *fp)
111 {
112 	wint_t		r;
113 	rmutex_t	*l;
114 	locale_t	loc = uselocale(NULL);
115 
116 	FLOCKFILE(l, fp);
117 	r = _fgetwc_unlocked_l(fp, loc);
118 	FUNLOCKFILE(l);
119 
120 	return (r);
121 }
122 
123 /*
124  * XPG5 version.
125  */
126 #undef	__getwc_xpg5
127 #pragma weak __getwc_xpg5 = __fgetwc_xpg5
128 wint_t
129 __fgetwc_xpg5(FILE *fp)
130 {
131 	wint_t		r;
132 	rmutex_t	*l;
133 	locale_t	loc = uselocale(NULL);
134 
135 	FLOCKFILE(l, fp);
136 	if (GET_NO_MODE(fp))
137 		_setorientation(fp, _WC_MODE);
138 	r = _fgetwc_unlocked_l(fp, loc);
139 	FUNLOCKFILE(l);
140 
141 	return (r);
142 }
143 
144 #pragma weak getwc_l = fgetwc_l
145 wint_t
146 fgetwc_l(FILE *fp, locale_t loc)
147 {
148 	wint_t		r;
149 	rmutex_t	*l;
150 	FLOCKFILE(l, fp);
151 	if (GET_NO_MODE(fp))
152 		_setorientation(fp, _WC_MODE);
153 	r = _fgetwc_unlocked_l(fp, loc);
154 	FUNLOCKFILE(l);
155 
156 	return (r);
157 }
158