NetBSD/sys/fs/unicode.h

131 lines
3.8 KiB
C

/* $NetBSD: unicode.h,v 1.2 2004/12/27 18:14:36 jdolecek Exp $ */
/*-
* Copyright (c) 2001, 2004 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Routines for handling Unicode encoded in UTF-8 form, code derived from
* src/lib/libc/locale/utf2.c.
*/
/*
* Read one UTF8-encoded character off the string, shift the string pointer
* and return the character.
*/
static u_int16_t
wget_utf8(const char **str, size_t *sz)
{
int c;
u_int16_t rune = 0;
const char *s = *str;
static const int _utf_count[16] = {
1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 2, 2, 3, 0,
};
/* must be called with at least one byte remaining */
KASSERT(*sz > 0);
c = _utf_count[(s[0] & 0xf0) >> 4];
if (c == 0 || c > *sz) {
decoding_error:
/*
* The first character is in range 128-255 and doesn't
* mark valid a valid UTF-8 sequence. There is not much
* we can do with this, so handle by returning
* the first character as if it would be a correctly
* encoded ISO-8859-1 character.
*/
c = 1;
}
switch (c) {
case 1:
rune = s[0] & 0xff;
break;
case 2:
if ((s[1] & 0xc0) != 0x80)
goto decoding_error;
rune = ((s[0] & 0x1F) << 6) | (s[1] & 0x3F);
break;
case 3:
if ((s[1] & 0xC0) != 0x80 || (s[2] & 0xC0) != 0x80)
goto decoding_error;
rune = ((s[0] & 0x1F) << 12) | ((s[1] & 0x3F) << 6)
| (s[2] & 0x3F);
break;
}
*str += c;
*sz -= c;
return rune;
}
/*
* Encode wide character and write it to the string. 'n' specifies
* how much buffer space remains in 's'. Returns number of bytes written
* to the target string 's'.
*/
static int
wput_utf8(char *s, size_t n, u_int16_t wc)
{
if (wc & 0xf800) {
if (n < 3) {
/* bound check failure */
return 0;
}
s[0] = 0xE0 | ((wc >> 12) & 0x0F);
s[1] = 0x80 | ((wc >> 6) & 0x3F);
s[2] = 0x80 | ((wc) & 0x3F);
return 3;
} else if (wc & 0x0780) {
if (n < 2) {
/* bound check failure */
return 0;
}
s[0] = 0xC0 | ((wc >> 6) & 0x1F);
s[1] = 0x80 | ((wc) & 0x3F);
return 2;
} else {
if (n < 1) {
/* bound check failure */
return 0;
}
s[0] = wc;
return 1;
}
}