1250883Sed/*-
2250883Sed * Copyright (c) 2013 Ed Schouten <ed@FreeBSD.org>
3250883Sed * All rights reserved.
4250883Sed *
5250883Sed * Redistribution and use in source and binary forms, with or without
6250883Sed * modification, are permitted provided that the following conditions
7250883Sed * are met:
8250883Sed * 1. Redistributions of source code must retain the above copyright
9250883Sed *    notice, this list of conditions and the following disclaimer.
10250883Sed * 2. Redistributions in binary form must reproduce the above copyright
11250883Sed *    notice, this list of conditions and the following disclaimer in the
12250883Sed *    documentation and/or other materials provided with the distribution.
13250883Sed *
14250883Sed * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15250883Sed * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16250883Sed * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17250883Sed * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18250883Sed * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19250883Sed * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20250883Sed * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21250883Sed * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22250883Sed * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23250883Sed * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24250883Sed * SUCH DAMAGE.
25250883Sed */
26250883Sed
27250883Sed#include <sys/cdefs.h>
28250883Sed__FBSDID("$FreeBSD$");
29250883Sed
30250883Sed#include <errno.h>
31250883Sed#include <uchar.h>
32250883Sed#include "xlocale_private.h"
33250883Sed
34250883Sedtypedef struct {
35250883Sed	char16_t	lead_surrogate;
36250883Sed	mbstate_t	c32_mbstate;
37250883Sed} _Char16State;
38250883Sed
39250883Sedsize_t
40250883Sedc16rtomb_l(char * __restrict s, char16_t c16, mbstate_t * __restrict ps,
41250883Sed    locale_t locale)
42250883Sed{
43250883Sed	_Char16State *cs;
44250883Sed	char32_t c32;
45250883Sed
46250883Sed	FIX_LOCALE(locale);
47250883Sed	if (ps == NULL)
48250883Sed		ps = &locale->c16rtomb;
49250883Sed	cs = (_Char16State *)ps;
50250883Sed
51250883Sed	/* If s is a null pointer, the value of parameter c16 is ignored. */
52250883Sed	if (s == NULL) {
53250883Sed		c32 = 0;
54250883Sed	} else if (cs->lead_surrogate >= 0xd800 &&
55250883Sed	    cs->lead_surrogate <= 0xdbff) {
56250883Sed		/* We should see a trail surrogate now. */
57250883Sed		if (c16 < 0xdc00 || c16 > 0xdfff) {
58250883Sed			errno = EILSEQ;
59250883Sed			return ((size_t)-1);
60250883Sed		}
61250883Sed		c32 = 0x10000 + ((cs->lead_surrogate & 0x3ff) << 10 |
62250883Sed		    (c16 & 0x3ff));
63250883Sed	} else if (c16 >= 0xd800 && c16 <= 0xdbff) {
64250883Sed		/* Store lead surrogate for next invocation. */
65250883Sed		cs->lead_surrogate = c16;
66250883Sed		return (0);
67250883Sed	} else {
68250883Sed		/* Regular character. */
69250883Sed		c32 = c16;
70250883Sed	}
71250883Sed	cs->lead_surrogate = 0;
72250883Sed
73250883Sed	return (c32rtomb_l(s, c32, &cs->c32_mbstate, locale));
74250883Sed}
75250883Sed
76250883Sedsize_t
77250883Sedc16rtomb(char * __restrict s, char16_t c16, mbstate_t * __restrict ps)
78250883Sed{
79250883Sed
80250883Sed	return (c16rtomb_l(s, c16, ps, __get_locale()));
81250883Sed}
82