xref: /freebsd/lib/libc/locale/mbrtocXX_iconv.h (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2013 Ed Schouten <ed@FreeBSD.org>
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 <sys/queue.h>
30 
31 #include <assert.h>
32 #include <errno.h>
33 #include <langinfo.h>
34 #include <limits.h>
35 #include <string.h>
36 #include <uchar.h>
37 
38 #include "../iconv/citrus_hash.h"
39 #include "../iconv/citrus_module.h"
40 #include "../iconv/citrus_iconv.h"
41 #include "mblocal.h"
42 
43 typedef struct {
44 	bool			initialized;
45 	struct _citrus_iconv	iconv;
46 	char			srcbuf[MB_LEN_MAX];
47 	size_t			srcbuf_len;
48 	union {
49 		charXX_t	widechar[DSTBUF_LEN];
50 		char		bytes[sizeof(charXX_t) * DSTBUF_LEN];
51 	} dstbuf;
52 	size_t			dstbuf_len;
53 } _ConversionState;
54 _Static_assert(sizeof(_ConversionState) <= sizeof(mbstate_t),
55     "Size of _ConversionState must not exceed mbstate_t's size.");
56 
57 size_t
58 mbrtocXX_l(charXX_t * __restrict pc, const char * __restrict s, size_t n,
59     mbstate_t * __restrict ps, locale_t locale)
60 {
61 	_ConversionState *cs;
62 	struct _citrus_iconv *handle;
63 	size_t i, retval;
64 	charXX_t retchar;
65 
66 	FIX_LOCALE(locale);
67 	if (ps == NULL)
68 		ps = &(XLOCALE_CTYPE(locale)->mbrtocXX);
69 	cs = (_ConversionState *)ps;
70 	handle = &cs->iconv;
71 
72 	/* Reinitialize mbstate_t. */
73 	if (s == NULL || !cs->initialized) {
74 		if (_citrus_iconv_open(&handle,
75 		    nl_langinfo_l(CODESET, locale), UTF_XX_INTERNAL) != 0) {
76 			cs->initialized = false;
77 			errno = EINVAL;
78 			return (-1);
79 		}
80 		cs->srcbuf_len = cs->dstbuf_len = 0;
81 		cs->initialized = true;
82 		if (s == NULL)
83 			return (0);
84 	}
85 
86 	/* See if we still have characters left from the previous invocation. */
87 	if (cs->dstbuf_len > 0) {
88 		retval = (size_t)-3;
89 		goto return_char;
90 	}
91 
92 	/* Fill up the read buffer as far as possible. */
93 	if (n > sizeof(cs->srcbuf) - cs->srcbuf_len)
94 		n = sizeof(cs->srcbuf) - cs->srcbuf_len;
95 	memcpy(cs->srcbuf + cs->srcbuf_len, s, n);
96 
97 	/* Convert as few characters to the dst buffer as possible. */
98 	for (i = 0; ; i++) {
99 		char *src, *dst;
100 		size_t srcleft, dstleft, invlen;
101 		int err;
102 
103 		src = cs->srcbuf;
104 		srcleft = cs->srcbuf_len + n;
105 		dst = cs->dstbuf.bytes;
106 		dstleft = i * sizeof(charXX_t);
107 		assert(srcleft <= sizeof(cs->srcbuf) &&
108 		    dstleft <= sizeof(cs->dstbuf.bytes));
109 		err = _citrus_iconv_convert(handle, &src, &srcleft,
110 		    &dst, &dstleft, _CITRUS_ICONV_F_HIDE_INVALID, &invlen);
111 		cs->dstbuf_len = (dst - cs->dstbuf.bytes) / sizeof(charXX_t);
112 
113 		/* Got new character(s). Return the first. */
114 		if (cs->dstbuf_len > 0) {
115 			assert(src - cs->srcbuf > cs->srcbuf_len);
116 			retval = src - cs->srcbuf - cs->srcbuf_len;
117 			cs->srcbuf_len = 0;
118 			goto return_char;
119 		}
120 
121 		/* Increase dst buffer size, to obtain the surrogate pair. */
122 		if (err == E2BIG)
123 			continue;
124 
125 		/* Illegal sequence. */
126 		if (invlen > 0) {
127 			cs->srcbuf_len = 0;
128 			errno = EILSEQ;
129 			return ((size_t)-1);
130 		}
131 
132 		/* Save unprocessed remainder for the next invocation. */
133 		memmove(cs->srcbuf, src, srcleft);
134 		cs->srcbuf_len = srcleft;
135 		return ((size_t)-2);
136 	}
137 
138 return_char:
139 	retchar = cs->dstbuf.widechar[0];
140 	memmove(&cs->dstbuf.widechar[0], &cs->dstbuf.widechar[1],
141 	    --cs->dstbuf_len * sizeof(charXX_t));
142 	if (pc != NULL)
143 		*pc = retchar;
144 	if (retchar == 0)
145 		return (0);
146 	return (retval);
147 }
148 
149 size_t
150 mbrtocXX(charXX_t * __restrict pc, const char * __restrict s, size_t n,
151     mbstate_t * __restrict ps)
152 {
153 
154 	return (mbrtocXX_l(pc, s, n, ps, __get_locale()));
155 }
156