xref: /titanic_50/usr/src/lib/libc/port/locale/mbrtoc16.c (revision 3fc10f8cbc2fd5dd5cd13044edf9cb68a1ef422b)
1*3fc10f8cSRobert Mustacchi /*
2*3fc10f8cSRobert Mustacchi  * This file and its contents are supplied under the terms of the
3*3fc10f8cSRobert Mustacchi  * Common Development and Distribution License ("CDDL"), version 1.0.
4*3fc10f8cSRobert Mustacchi  * You may only use this file in accordance with the terms of version
5*3fc10f8cSRobert Mustacchi  * 1.0 of the CDDL.
6*3fc10f8cSRobert Mustacchi  *
7*3fc10f8cSRobert Mustacchi  * A full copy of the text of the CDDL should have accompanied this
8*3fc10f8cSRobert Mustacchi  * source.  A copy of the CDDL is also available via the Internet at
9*3fc10f8cSRobert Mustacchi  * http://www.illumos.org/license/CDDL.
10*3fc10f8cSRobert Mustacchi  */
11*3fc10f8cSRobert Mustacchi 
12*3fc10f8cSRobert Mustacchi /*
13*3fc10f8cSRobert Mustacchi  * Copyright 2020 Robert Mustacchi
14*3fc10f8cSRobert Mustacchi  */
15*3fc10f8cSRobert Mustacchi 
16*3fc10f8cSRobert Mustacchi /*
17*3fc10f8cSRobert Mustacchi  * C11 mbrtoc16(3C) support.
18*3fc10f8cSRobert Mustacchi  *
19*3fc10f8cSRobert Mustacchi  * The char16_t represents a UTF-16 encoding. This means that we have to deal
20*3fc10f8cSRobert Mustacchi  * with surrogate pairs.
21*3fc10f8cSRobert Mustacchi  */
22*3fc10f8cSRobert Mustacchi 
23*3fc10f8cSRobert Mustacchi #include <locale.h>
24*3fc10f8cSRobert Mustacchi #include <wchar.h>
25*3fc10f8cSRobert Mustacchi #include <xlocale.h>
26*3fc10f8cSRobert Mustacchi #include <uchar.h>
27*3fc10f8cSRobert Mustacchi #include "mblocal.h"
28*3fc10f8cSRobert Mustacchi #include "unicode.h"
29*3fc10f8cSRobert Mustacchi 
30*3fc10f8cSRobert Mustacchi #include <sys/debug.h>
31*3fc10f8cSRobert Mustacchi 
32*3fc10f8cSRobert Mustacchi /*
33*3fc10f8cSRobert Mustacchi  * Ensure that we never cause our save state to ever exceed that of the
34*3fc10f8cSRobert Mustacchi  * mbstate_t. See the block comment in mblocal.h.
35*3fc10f8cSRobert Mustacchi  */
36*3fc10f8cSRobert Mustacchi CTASSERT(sizeof (_CHAR16State) <= sizeof (mbstate_t));
37*3fc10f8cSRobert Mustacchi 
38*3fc10f8cSRobert Mustacchi static mbstate_t mbrtoc16_state;
39*3fc10f8cSRobert Mustacchi 
40*3fc10f8cSRobert Mustacchi size_t
mbrtoc16(char16_t * restrict pc16,const char * restrict str,size_t len,mbstate_t * restrict ps)41*3fc10f8cSRobert Mustacchi mbrtoc16(char16_t *restrict pc16, const char *restrict str, size_t len,
42*3fc10f8cSRobert Mustacchi     mbstate_t *restrict ps)
43*3fc10f8cSRobert Mustacchi {
44*3fc10f8cSRobert Mustacchi 	wchar_t wc;
45*3fc10f8cSRobert Mustacchi 	size_t ret;
46*3fc10f8cSRobert Mustacchi 	char16_t out;
47*3fc10f8cSRobert Mustacchi 	_CHAR16State *c16s;
48*3fc10f8cSRobert Mustacchi 
49*3fc10f8cSRobert Mustacchi 	if (ps == NULL) {
50*3fc10f8cSRobert Mustacchi 		ps = &mbrtoc16_state;
51*3fc10f8cSRobert Mustacchi 	}
52*3fc10f8cSRobert Mustacchi 
53*3fc10f8cSRobert Mustacchi 	if (str == NULL) {
54*3fc10f8cSRobert Mustacchi 		pc16 = NULL;
55*3fc10f8cSRobert Mustacchi 		str = "";
56*3fc10f8cSRobert Mustacchi 		len = 1;
57*3fc10f8cSRobert Mustacchi 	}
58*3fc10f8cSRobert Mustacchi 
59*3fc10f8cSRobert Mustacchi 	c16s = (_CHAR16State *)ps;
60*3fc10f8cSRobert Mustacchi 	if (c16s->c16_surrogate != 0) {
61*3fc10f8cSRobert Mustacchi 		if (pc16 != NULL) {
62*3fc10f8cSRobert Mustacchi 			*pc16 = c16s->c16_surrogate;
63*3fc10f8cSRobert Mustacchi 		}
64*3fc10f8cSRobert Mustacchi 		c16s->c16_surrogate = 0;
65*3fc10f8cSRobert Mustacchi 		return ((size_t)-3);
66*3fc10f8cSRobert Mustacchi 	}
67*3fc10f8cSRobert Mustacchi 
68*3fc10f8cSRobert Mustacchi 	ret = mbrtowc_l(&wc, str, len, ps, uselocale(NULL));
69*3fc10f8cSRobert Mustacchi 	if ((ssize_t)ret < 0) {
70*3fc10f8cSRobert Mustacchi 		return (ret);
71*3fc10f8cSRobert Mustacchi 	}
72*3fc10f8cSRobert Mustacchi 
73*3fc10f8cSRobert Mustacchi 	/*
74*3fc10f8cSRobert Mustacchi 	 * If this character is not in the basic multilingual plane then we need
75*3fc10f8cSRobert Mustacchi 	 * a surrogate character to represent it in UTF-16 and we will need to
76*3fc10f8cSRobert Mustacchi 	 * write that out on the next iteration.
77*3fc10f8cSRobert Mustacchi 	 */
78*3fc10f8cSRobert Mustacchi 	if (wc >= UNICODE_SUP_START) {
79*3fc10f8cSRobert Mustacchi 		wc -= UNICODE_SUP_START;
80*3fc10f8cSRobert Mustacchi 		c16s->c16_surrogate = UNICODE_SUR_LOWER | UNICODE_SUR_LMASK(wc);
81*3fc10f8cSRobert Mustacchi 		out = UNICODE_SUR_UPPER | UNICODE_SUR_UMASK(wc);
82*3fc10f8cSRobert Mustacchi 	} else {
83*3fc10f8cSRobert Mustacchi 		out = (char16_t)wc;
84*3fc10f8cSRobert Mustacchi 	}
85*3fc10f8cSRobert Mustacchi 
86*3fc10f8cSRobert Mustacchi 	if (pc16 != NULL) {
87*3fc10f8cSRobert Mustacchi 		*pc16 = out;
88*3fc10f8cSRobert Mustacchi 	}
89*3fc10f8cSRobert Mustacchi 
90*3fc10f8cSRobert Mustacchi 	return (ret);
91*3fc10f8cSRobert Mustacchi }
92