xref: /freebsd/lib/libc/locale/c16rtomb.c (revision 4d846d260e2b9a3d4d0a701462568268cbfe7a5b)
150c77c6eSEd Schouten /*-
2*4d846d26SWarner Losh  * SPDX-License-Identifier: BSD-2-Clause
3d915a14eSPedro F. Giffuni  *
450c77c6eSEd Schouten  * Copyright (c) 2013 Ed Schouten <ed@FreeBSD.org>
550c77c6eSEd Schouten  * All rights reserved.
650c77c6eSEd Schouten  *
750c77c6eSEd Schouten  * Redistribution and use in source and binary forms, with or without
850c77c6eSEd Schouten  * modification, are permitted provided that the following conditions
950c77c6eSEd Schouten  * are met:
1050c77c6eSEd Schouten  * 1. Redistributions of source code must retain the above copyright
1150c77c6eSEd Schouten  *    notice, this list of conditions and the following disclaimer.
1250c77c6eSEd Schouten  * 2. Redistributions in binary form must reproduce the above copyright
1350c77c6eSEd Schouten  *    notice, this list of conditions and the following disclaimer in the
1450c77c6eSEd Schouten  *    documentation and/or other materials provided with the distribution.
1550c77c6eSEd Schouten  *
1650c77c6eSEd Schouten  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1750c77c6eSEd Schouten  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1850c77c6eSEd Schouten  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1950c77c6eSEd Schouten  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
2050c77c6eSEd Schouten  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2150c77c6eSEd Schouten  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2250c77c6eSEd Schouten  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2350c77c6eSEd Schouten  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2450c77c6eSEd Schouten  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2550c77c6eSEd Schouten  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2650c77c6eSEd Schouten  * SUCH DAMAGE.
2750c77c6eSEd Schouten  */
2850c77c6eSEd Schouten 
2950c77c6eSEd Schouten #include <sys/cdefs.h>
3050c77c6eSEd Schouten __FBSDID("$FreeBSD$");
3150c77c6eSEd Schouten 
3250c77c6eSEd Schouten #include <errno.h>
3350c77c6eSEd Schouten #include <uchar.h>
3498f3acfaSYuri Pankov #include "mblocal.h"
3550c77c6eSEd Schouten 
3650c77c6eSEd Schouten typedef struct {
3750c77c6eSEd Schouten 	char16_t	lead_surrogate;
3850c77c6eSEd Schouten 	mbstate_t	c32_mbstate;
3950c77c6eSEd Schouten } _Char16State;
4050c77c6eSEd Schouten 
4150c77c6eSEd Schouten size_t
4250c77c6eSEd Schouten c16rtomb_l(char * __restrict s, char16_t c16, mbstate_t * __restrict ps,
4350c77c6eSEd Schouten     locale_t locale)
4450c77c6eSEd Schouten {
4550c77c6eSEd Schouten 	_Char16State *cs;
4650c77c6eSEd Schouten 	char32_t c32;
4750c77c6eSEd Schouten 
4850c77c6eSEd Schouten 	FIX_LOCALE(locale);
4950c77c6eSEd Schouten 	if (ps == NULL)
5098f3acfaSYuri Pankov 		ps = &(XLOCALE_CTYPE(locale)->c16rtomb);
5150c77c6eSEd Schouten 	cs = (_Char16State *)ps;
5250c77c6eSEd Schouten 
5350c77c6eSEd Schouten 	/* If s is a null pointer, the value of parameter c16 is ignored. */
5450c77c6eSEd Schouten 	if (s == NULL) {
5550c77c6eSEd Schouten 		c32 = 0;
5650c77c6eSEd Schouten 	} else if (cs->lead_surrogate >= 0xd800 &&
5750c77c6eSEd Schouten 	    cs->lead_surrogate <= 0xdbff) {
5850c77c6eSEd Schouten 		/* We should see a trail surrogate now. */
5950c77c6eSEd Schouten 		if (c16 < 0xdc00 || c16 > 0xdfff) {
6050c77c6eSEd Schouten 			errno = EILSEQ;
6150c77c6eSEd Schouten 			return ((size_t)-1);
6250c77c6eSEd Schouten 		}
6350c77c6eSEd Schouten 		c32 = 0x10000 + ((cs->lead_surrogate & 0x3ff) << 10 |
6450c77c6eSEd Schouten 		    (c16 & 0x3ff));
6550c77c6eSEd Schouten 	} else if (c16 >= 0xd800 && c16 <= 0xdbff) {
6650c77c6eSEd Schouten 		/* Store lead surrogate for next invocation. */
6750c77c6eSEd Schouten 		cs->lead_surrogate = c16;
6850c77c6eSEd Schouten 		return (0);
6950c77c6eSEd Schouten 	} else {
7050c77c6eSEd Schouten 		/* Regular character. */
7150c77c6eSEd Schouten 		c32 = c16;
7250c77c6eSEd Schouten 	}
7350c77c6eSEd Schouten 	cs->lead_surrogate = 0;
7450c77c6eSEd Schouten 
7550c77c6eSEd Schouten 	return (c32rtomb_l(s, c32, &cs->c32_mbstate, locale));
7650c77c6eSEd Schouten }
7750c77c6eSEd Schouten 
7850c77c6eSEd Schouten size_t
7950c77c6eSEd Schouten c16rtomb(char * __restrict s, char16_t c16, mbstate_t * __restrict ps)
8050c77c6eSEd Schouten {
8150c77c6eSEd Schouten 
8250c77c6eSEd Schouten 	return (c16rtomb_l(s, c16, ps, __get_locale()));
8350c77c6eSEd Schouten }
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