c16rtomb.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/cdefs.h>
30__FBSDID("$FreeBSD: stable/11/lib/libc/locale/c16rtomb.c 330897 2018-03-14 03:19:51Z eadler $");
31
32#include <errno.h>
33#include <uchar.h>
34#include "xlocale_private.h"
35
36typedef struct {
37	char16_t	lead_surrogate;
38	mbstate_t	c32_mbstate;
39} _Char16State;
40
41size_t
42c16rtomb_l(char * __restrict s, char16_t c16, mbstate_t * __restrict ps,
43    locale_t locale)
44{
45	_Char16State *cs;
46	char32_t c32;
47
48	FIX_LOCALE(locale);
49	if (ps == NULL)
50		ps = &locale->c16rtomb;
51	cs = (_Char16State *)ps;
52
53	/* If s is a null pointer, the value of parameter c16 is ignored. */
54	if (s == NULL) {
55		c32 = 0;
56	} else if (cs->lead_surrogate >= 0xd800 &&
57	    cs->lead_surrogate <= 0xdbff) {
58		/* We should see a trail surrogate now. */
59		if (c16 < 0xdc00 || c16 > 0xdfff) {
60			errno = EILSEQ;
61			return ((size_t)-1);
62		}
63		c32 = 0x10000 + ((cs->lead_surrogate & 0x3ff) << 10 |
64		    (c16 & 0x3ff));
65	} else if (c16 >= 0xd800 && c16 <= 0xdbff) {
66		/* Store lead surrogate for next invocation. */
67		cs->lead_surrogate = c16;
68		return (0);
69	} else {
70		/* Regular character. */
71		c32 = c16;
72	}
73	cs->lead_surrogate = 0;
74
75	return (c32rtomb_l(s, c32, &cs->c32_mbstate, locale));
76}
77
78size_t
79c16rtomb(char * __restrict s, char16_t c16, mbstate_t * __restrict ps)
80{
81
82	return (c16rtomb_l(s, c16, ps, __get_locale()));
83}
84