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freebsd/lib/libc/locale/utf8.c
2003-11-11 07:25:05 +00:00

203 lines
5.2 KiB
C

/*-
* Copyright (c) 2002, 2003 Tim J. Robbins
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <runetype.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>
extern size_t (*__mbrtowc)(wchar_t * __restrict, const char * __restrict,
size_t, mbstate_t * __restrict);
extern size_t (*__wcrtomb)(char * __restrict, wchar_t, mbstate_t * __restrict);
size_t _UTF8_mbrtowc(wchar_t * __restrict, const char * __restrict, size_t,
mbstate_t * __restrict);
size_t _UTF8_wcrtomb(char * __restrict, wchar_t, mbstate_t * __restrict);
int
_UTF8_init(_RuneLocale *rl)
{
__mbrtowc = _UTF8_mbrtowc;
__wcrtomb = _UTF8_wcrtomb;
_CurrentRuneLocale = rl;
__mb_cur_max = 6;
return (0);
}
size_t
_UTF8_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
mbstate_t * __restrict ps __unused)
{
int ch, i, len, mask;
wchar_t lbound, wch;
if (s == NULL)
/* Reset to initial shift state (no-op) */
return (0);
if (n == 0)
/* Incomplete multibyte sequence */
return ((size_t)-2);
/*
* Determine the number of octets that make up this character from
* the first octet, and a mask that extracts the interesting bits of
* the first octet.
*
* We also specify a lower bound for the character code to detect
* redundant, non-"shortest form" encodings. For example, the
* sequence C0 80 is _not_ a legal representation of the null
* character. This enforces a 1-to-1 mapping between character
* codes and their multibyte representations.
*/
ch = (unsigned char)*s;
if ((ch & 0x80) == 0) {
mask = 0x7f;
len = 1;
lbound = 0;
} else if ((ch & 0xe0) == 0xc0) {
mask = 0x1f;
len = 2;
lbound = 0x80;
} else if ((ch & 0xf0) == 0xe0) {
mask = 0x0f;
len = 3;
lbound = 0x800;
} else if ((ch & 0xf8) == 0xf0) {
mask = 0x07;
len = 4;
lbound = 0x10000;
} else if ((ch & 0xfc) == 0xf8) {
mask = 0x03;
len = 5;
lbound = 0x200000;
} else if ((ch & 0xfc) == 0xfc) {
mask = 0x01;
len = 6;
lbound = 0x4000000;
} else {
/*
* Malformed input; input is not UTF-8.
*/
errno = EILSEQ;
return ((size_t)-1);
}
if (n < (size_t)len)
/* Incomplete multibyte sequence */
return ((size_t)-2);
/*
* Decode the octet sequence representing the character in chunks
* of 6 bits, most significant first.
*/
wch = (unsigned char)*s++ & mask;
i = len;
while (--i != 0) {
if ((*s & 0xc0) != 0x80) {
/*
* Malformed input; bad characters in the middle
* of a character.
*/
errno = EILSEQ;
return ((size_t)-1);
}
wch <<= 6;
wch |= *s++ & 0x3f;
}
if (wch < lbound) {
/*
* Malformed input; redundant encoding.
*/
errno = EILSEQ;
return ((size_t)-1);
}
if (pwc != NULL)
*pwc = wch;
return (wch == L'\0' ? 0 : len);
}
size_t
_UTF8_wcrtomb(char * __restrict s, wchar_t wc,
mbstate_t * __restrict ps __unused)
{
unsigned char lead;
int i, len;
if (s == NULL)
/* Reset to initial shift state (no-op) */
return (1);
/*
* Determine the number of octets needed to represent this character.
* We always output the shortest sequence possible. Also specify the
* first few bits of the first octet, which contains the information
* about the sequence length.
*/
if ((wc & ~0x7f) == 0) {
lead = 0;
len = 1;
} else if ((wc & ~0x7ff) == 0) {
lead = 0xc0;
len = 2;
} else if ((wc & ~0xffff) == 0) {
lead = 0xe0;
len = 3;
} else if ((wc & ~0x1fffff) == 0) {
lead = 0xf0;
len = 4;
} else if ((wc & ~0x3ffffff) == 0) {
lead = 0xf8;
len = 5;
} else if ((wc & ~0x7fffffff) == 0) {
lead = 0xfc;
len = 6;
} else {
errno = EILSEQ;
return ((size_t)-1);
}
/*
* Output the octets representing the character in chunks
* of 6 bits, least significant last. The first octet is
* a special case because it contains the sequence length
* information.
*/
for (i = len - 1; i > 0; i--) {
s[i] = (wc & 0x3f) | 0x80;
wc >>= 6;
}
*s = (wc & 0xff) | lead;
return (len);
}