xref: /illumos-gate/usr/src/lib/libc/port/locale/fgetwc.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
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 	statep = _getmbstate(fp);
63 	if (statep == NULL) {
64 		fp->_flag = _IOERR;
65 		errno = EBADF;
66 		return (WEOF);
67 	}
68 	do {
69 		char	x = (char)c;
70 		nconv = lct->lc_mbrtowc(&wc, &x, 1, statep, B_FALSE);
71 		if (nconv == (size_t)-1) {
72 			break;
73 		} else if (nconv == (size_t)-2) {
74 			/* Incompletely decoded, consume another char */
75 			continue;
76 		} else if (nconv == 0) {
77 			/*
78 			 * Assume that the only valid representation of
79 			 * the null wide character is a single null byte.
80 			 */
81 			return (L'\0');
82 		} else {
83 			return (wc);
84 		}
85 	} while ((c = GETC(fp)) != EOF);
86 
87 	/*
88 	 * If we got here it means we got truncated in a character, or
89 	 * the character did not decode properly.  Note that in the case
90 	 * of a botched decoding, we don't UNGETC the bad bytes.  Should
91 	 * we?
92 	 */
93 	fp->_flag |= _IOERR;
94 	errno = EILSEQ;
95 	return (WEOF);
96 }
97 
98 wint_t
99 _fgetwc_unlocked(FILE *fp)
100 {
101 	return (_fgetwc_unlocked_l(fp, uselocale(NULL)));
102 }
103 
104 
105 /*
106  * MT safe version
107  */
108 #undef getwc
109 #pragma weak getwc = fgetwc
110 wint_t
111 fgetwc(FILE *fp)
112 {
113 	wint_t		r;
114 	rmutex_t	*l;
115 	locale_t	loc = uselocale(NULL);
116 
117 	FLOCKFILE(l, fp);
118 	r = _fgetwc_unlocked_l(fp, loc);
119 	FUNLOCKFILE(l);
120 
121 	return (r);
122 }
123 
124 /*
125  * XPG5 version.
126  */
127 #undef	__getwc_xpg5
128 #pragma weak __getwc_xpg5 = __fgetwc_xpg5
129 wint_t
130 __fgetwc_xpg5(FILE *fp)
131 {
132 	wint_t		r;
133 	rmutex_t	*l;
134 	locale_t	loc = uselocale(NULL);
135 
136 	FLOCKFILE(l, fp);
137 	if (GET_NO_MODE(fp))
138 		_setorientation(fp, _WC_MODE);
139 	r = _fgetwc_unlocked_l(fp, loc);
140 	FUNLOCKFILE(l);
141 
142 	return (r);
143 }
144 
145 #pragma weak getwc_l = fgetwc_l
146 wint_t
147 fgetwc_l(FILE *fp, locale_t loc)
148 {
149 	wint_t		r;
150 	rmutex_t	*l;
151 	FLOCKFILE(l, fp);
152 	if (GET_NO_MODE(fp))
153 		_setorientation(fp, _WC_MODE);
154 	r = _fgetwc_unlocked_l(fp, loc);
155 	FUNLOCKFILE(l);
156 
157 	return (r);
158 }
159