xref: /titanic_52/usr/src/lib/libc/port/locale/mbrtoc16.c (revision 9a4a12bd7ce60cd60eae508b25eb7a8dae765274)
1*9a4a12bdSRobert Mustacchi /*
2*9a4a12bdSRobert Mustacchi  * This file and its contents are supplied under the terms of the
3*9a4a12bdSRobert Mustacchi  * Common Development and Distribution License ("CDDL"), version 1.0.
4*9a4a12bdSRobert Mustacchi  * You may only use this file in accordance with the terms of version
5*9a4a12bdSRobert Mustacchi  * 1.0 of the CDDL.
6*9a4a12bdSRobert Mustacchi  *
7*9a4a12bdSRobert Mustacchi  * A full copy of the text of the CDDL should have accompanied this
8*9a4a12bdSRobert Mustacchi  * source.  A copy of the CDDL is also available via the Internet at
9*9a4a12bdSRobert Mustacchi  * http://www.illumos.org/license/CDDL.
10*9a4a12bdSRobert Mustacchi  */
11*9a4a12bdSRobert Mustacchi 
12*9a4a12bdSRobert Mustacchi /*
13*9a4a12bdSRobert Mustacchi  * Copyright 2020 Robert Mustacchi
14*9a4a12bdSRobert Mustacchi  */
15*9a4a12bdSRobert Mustacchi 
16*9a4a12bdSRobert Mustacchi /*
17*9a4a12bdSRobert Mustacchi  * C11 mbrtoc16(3C) support.
18*9a4a12bdSRobert Mustacchi  *
19*9a4a12bdSRobert Mustacchi  * The char16_t represents a UTF-16 encoding. This means that we have to deal
20*9a4a12bdSRobert Mustacchi  * with surrogate pairs.
21*9a4a12bdSRobert Mustacchi  */
22*9a4a12bdSRobert Mustacchi 
23*9a4a12bdSRobert Mustacchi #include <locale.h>
24*9a4a12bdSRobert Mustacchi #include <wchar.h>
25*9a4a12bdSRobert Mustacchi #include <xlocale.h>
26*9a4a12bdSRobert Mustacchi #include <uchar.h>
27*9a4a12bdSRobert Mustacchi #include "mblocal.h"
28*9a4a12bdSRobert Mustacchi #include "unicode.h"
29*9a4a12bdSRobert Mustacchi 
30*9a4a12bdSRobert Mustacchi #include <sys/debug.h>
31*9a4a12bdSRobert Mustacchi 
32*9a4a12bdSRobert Mustacchi /*
33*9a4a12bdSRobert Mustacchi  * Ensure that we never cause our save state to ever exceed that of the
34*9a4a12bdSRobert Mustacchi  * mbstate_t. See the block comment in mblocal.h.
35*9a4a12bdSRobert Mustacchi  */
36*9a4a12bdSRobert Mustacchi CTASSERT(sizeof (_CHAR16State) <= sizeof (mbstate_t));
37*9a4a12bdSRobert Mustacchi 
38*9a4a12bdSRobert Mustacchi static mbstate_t mbrtoc16_state;
39*9a4a12bdSRobert Mustacchi 
40*9a4a12bdSRobert Mustacchi size_t
41*9a4a12bdSRobert Mustacchi mbrtoc16(char16_t *restrict pc16, const char *restrict str, size_t len,
42*9a4a12bdSRobert Mustacchi     mbstate_t *restrict ps)
43*9a4a12bdSRobert Mustacchi {
44*9a4a12bdSRobert Mustacchi 	wchar_t wc;
45*9a4a12bdSRobert Mustacchi 	size_t ret;
46*9a4a12bdSRobert Mustacchi 	char16_t out;
47*9a4a12bdSRobert Mustacchi 	_CHAR16State *c16s;
48*9a4a12bdSRobert Mustacchi 
49*9a4a12bdSRobert Mustacchi 	if (ps == NULL) {
50*9a4a12bdSRobert Mustacchi 		ps = &mbrtoc16_state;
51*9a4a12bdSRobert Mustacchi 	}
52*9a4a12bdSRobert Mustacchi 
53*9a4a12bdSRobert Mustacchi 	if (str == NULL) {
54*9a4a12bdSRobert Mustacchi 		pc16 = NULL;
55*9a4a12bdSRobert Mustacchi 		str = "";
56*9a4a12bdSRobert Mustacchi 		len = 1;
57*9a4a12bdSRobert Mustacchi 	}
58*9a4a12bdSRobert Mustacchi 
59*9a4a12bdSRobert Mustacchi 	c16s = (_CHAR16State *)ps;
60*9a4a12bdSRobert Mustacchi 	if (c16s->c16_surrogate != 0) {
61*9a4a12bdSRobert Mustacchi 		if (pc16 != NULL) {
62*9a4a12bdSRobert Mustacchi 			*pc16 = c16s->c16_surrogate;
63*9a4a12bdSRobert Mustacchi 		}
64*9a4a12bdSRobert Mustacchi 		c16s->c16_surrogate = 0;
65*9a4a12bdSRobert Mustacchi 		return ((size_t)-3);
66*9a4a12bdSRobert Mustacchi 	}
67*9a4a12bdSRobert Mustacchi 
68*9a4a12bdSRobert Mustacchi 	ret = mbrtowc_l(&wc, str, len, ps, uselocale(NULL));
69*9a4a12bdSRobert Mustacchi 	if ((ssize_t)ret < 0) {
70*9a4a12bdSRobert Mustacchi 		return (ret);
71*9a4a12bdSRobert Mustacchi 	}
72*9a4a12bdSRobert Mustacchi 
73*9a4a12bdSRobert Mustacchi 	/*
74*9a4a12bdSRobert Mustacchi 	 * If this character is not in the basic multilingual plane then we need
75*9a4a12bdSRobert Mustacchi 	 * a surrogate character to represent it in UTF-16 and we will need to
76*9a4a12bdSRobert Mustacchi 	 * write that out on the next iteration.
77*9a4a12bdSRobert Mustacchi 	 */
78*9a4a12bdSRobert Mustacchi 	if (wc >= UNICODE_SUP_START) {
79*9a4a12bdSRobert Mustacchi 		wc -= UNICODE_SUP_START;
80*9a4a12bdSRobert Mustacchi 		c16s->c16_surrogate = UNICODE_SUR_LOWER | UNICODE_SUR_LMASK(wc);
81*9a4a12bdSRobert Mustacchi 		out = UNICODE_SUR_UPPER | UNICODE_SUR_UMASK(wc);
82*9a4a12bdSRobert Mustacchi 	} else {
83*9a4a12bdSRobert Mustacchi 		out = (char16_t)wc;
84*9a4a12bdSRobert Mustacchi 	}
85*9a4a12bdSRobert Mustacchi 
86*9a4a12bdSRobert Mustacchi 	if (pc16 != NULL) {
87*9a4a12bdSRobert Mustacchi 		*pc16 = out;
88*9a4a12bdSRobert Mustacchi 	}
89*9a4a12bdSRobert Mustacchi 
90*9a4a12bdSRobert Mustacchi 	return (ret);
91*9a4a12bdSRobert Mustacchi }
92