freebsd-dev/lib/libc/locale/utf8.c
2007-10-15 09:51:30 +00:00

430 lines
9.8 KiB
C

/*-
* Copyright (c) 2002-2004 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/param.h>
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <limits.h>
#include <runetype.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include "mblocal.h"
extern int __mb_sb_limit;
static size_t _UTF8_mbrtowc(wchar_t * __restrict, const char * __restrict,
size_t, mbstate_t * __restrict);
static int _UTF8_mbsinit(const mbstate_t *);
static size_t _UTF8_mbsnrtowcs(wchar_t * __restrict,
const char ** __restrict, size_t, size_t,
mbstate_t * __restrict);
static size_t _UTF8_wcrtomb(char * __restrict, wchar_t,
mbstate_t * __restrict);
static size_t _UTF8_wcsnrtombs(char * __restrict, const wchar_t ** __restrict,
size_t, size_t, mbstate_t * __restrict);
typedef struct {
wchar_t ch;
int want;
wchar_t lbound;
} _UTF8State;
int
_UTF8_init(_RuneLocale *rl)
{
__mbrtowc = _UTF8_mbrtowc;
__wcrtomb = _UTF8_wcrtomb;
__mbsinit = _UTF8_mbsinit;
__mbsnrtowcs = _UTF8_mbsnrtowcs;
__wcsnrtombs = _UTF8_wcsnrtombs;
_CurrentRuneLocale = rl;
__mb_cur_max = 6;
/*
* UCS-4 encoding used as the internal representation, so
* slots 0x0080-0x00FF are occuped and must be excluded
* from the single byte ctype by setting the limit.
*/
__mb_sb_limit = 128;
return (0);
}
static int
_UTF8_mbsinit(const mbstate_t *ps)
{
return (ps == NULL || ((const _UTF8State *)ps)->want == 0);
}
static size_t
_UTF8_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
mbstate_t * __restrict ps)
{
_UTF8State *us;
int ch, i, mask, want;
wchar_t lbound, wch;
us = (_UTF8State *)ps;
if (us->want < 0 || us->want > 6) {
errno = EINVAL;
return ((size_t)-1);
}
if (s == NULL) {
s = "";
n = 1;
pwc = NULL;
}
if (n == 0)
/* Incomplete multibyte sequence */
return ((size_t)-2);
if (us->want == 0 && ((ch = (unsigned char)*s) & ~0x7f) == 0) {
/* Fast path for plain ASCII characters. */
if (pwc != NULL)
*pwc = ch;
return (ch != '\0' ? 1 : 0);
}
if (us->want == 0) {
/*
* 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 already know
* the character is at least two bytes long.
*
* 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;
want = 1;
lbound = 0;
} else if ((ch & 0xe0) == 0xc0) {
mask = 0x1f;
want = 2;
lbound = 0x80;
} else if ((ch & 0xf0) == 0xe0) {
mask = 0x0f;
want = 3;
lbound = 0x800;
} else if ((ch & 0xf8) == 0xf0) {
mask = 0x07;
want = 4;
lbound = 0x10000;
} else if ((ch & 0xfc) == 0xf8) {
mask = 0x03;
want = 5;
lbound = 0x200000;
} else if ((ch & 0xfe) == 0xfc) {
mask = 0x01;
want = 6;
lbound = 0x4000000;
} else {
/*
* Malformed input; input is not UTF-8.
*/
errno = EILSEQ;
return ((size_t)-1);
}
} else {
want = us->want;
lbound = us->lbound;
}
/*
* Decode the octet sequence representing the character in chunks
* of 6 bits, most significant first.
*/
if (us->want == 0)
wch = (unsigned char)*s++ & mask;
else
wch = us->ch;
for (i = (us->want == 0) ? 1 : 0; i < MIN(want, n); i++) {
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 (i < want) {
/* Incomplete multibyte sequence. */
us->want = want - i;
us->lbound = lbound;
us->ch = wch;
return ((size_t)-2);
}
if (wch < lbound) {
/*
* Malformed input; redundant encoding.
*/
errno = EILSEQ;
return ((size_t)-1);
}
if (pwc != NULL)
*pwc = wch;
us->want = 0;
return (wch == L'\0' ? 0 : want);
}
static size_t
_UTF8_mbsnrtowcs(wchar_t * __restrict dst, const char ** __restrict src,
size_t nms, size_t len, mbstate_t * __restrict ps)
{
_UTF8State *us;
const char *s;
size_t nchr;
wchar_t wc;
size_t nb;
us = (_UTF8State *)ps;
s = *src;
nchr = 0;
if (dst == NULL) {
/*
* The fast path in the loop below is not safe if an ASCII
* character appears as anything but the first byte of a
* multibyte sequence. Check now to avoid doing it in the loop.
*/
if (nms > 0 && us->want > 0 && (signed char)*s > 0) {
errno = EILSEQ;
return ((size_t)-1);
}
for (;;) {
if (nms > 0 && (signed char)*s > 0)
/*
* Fast path for plain ASCII characters
* excluding NUL.
*/
nb = 1;
else if ((nb = _UTF8_mbrtowc(&wc, s, nms, ps)) ==
(size_t)-1)
/* Invalid sequence - mbrtowc() sets errno. */
return ((size_t)-1);
else if (nb == 0 || nb == (size_t)-2)
return (nchr);
s += nb;
nms -= nb;
nchr++;
}
/*NOTREACHED*/
}
/*
* The fast path in the loop below is not safe if an ASCII
* character appears as anything but the first byte of a
* multibyte sequence. Check now to avoid doing it in the loop.
*/
if (nms > 0 && len > 0 && us->want > 0 && (signed char)*s > 0) {
errno = EILSEQ;
return ((size_t)-1);
}
while (len-- > 0) {
if (nms > 0 && (signed char)*s > 0) {
/*
* Fast path for plain ASCII characters
* excluding NUL.
*/
*dst = (wchar_t)*s;
nb = 1;
} else if ((nb = _UTF8_mbrtowc(dst, s, nms, ps)) ==
(size_t)-1) {
*src = s;
return ((size_t)-1);
} else if (nb == (size_t)-2) {
*src = s + nms;
return (nchr);
} else if (nb == 0) {
*src = NULL;
return (nchr);
}
s += nb;
nms -= nb;
nchr++;
dst++;
}
*src = s;
return (nchr);
}
static size_t
_UTF8_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
{
_UTF8State *us;
unsigned char lead;
int i, len;
us = (_UTF8State *)ps;
if (us->want != 0) {
errno = EINVAL;
return ((size_t)-1);
}
if (s == NULL)
/* Reset to initial shift state (no-op) */
return (1);
if ((wc & ~0x7f) == 0) {
/* Fast path for plain ASCII characters. */
*s = (char)wc;
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);
}
static size_t
_UTF8_wcsnrtombs(char * __restrict dst, const wchar_t ** __restrict src,
size_t nwc, size_t len, mbstate_t * __restrict ps)
{
_UTF8State *us;
char buf[MB_LEN_MAX];
const wchar_t *s;
size_t nbytes;
size_t nb;
us = (_UTF8State *)ps;
if (us->want != 0) {
errno = EINVAL;
return ((size_t)-1);
}
s = *src;
nbytes = 0;
if (dst == NULL) {
while (nwc-- > 0) {
if (0 <= *s && *s < 0x80)
/* Fast path for plain ASCII characters. */
nb = 1;
else if ((nb = _UTF8_wcrtomb(buf, *s, ps)) ==
(size_t)-1)
/* Invalid character - wcrtomb() sets errno. */
return ((size_t)-1);
if (*s == L'\0')
return (nbytes + nb - 1);
s++;
nbytes += nb;
}
return (nbytes);
}
while (len > 0 && nwc-- > 0) {
if (0 <= *s && *s < 0x80) {
/* Fast path for plain ASCII characters. */
nb = 1;
*dst = *s;
} else if (len > (size_t)MB_CUR_MAX) {
/* Enough space to translate in-place. */
if ((nb = _UTF8_wcrtomb(dst, *s, ps)) == (size_t)-1) {
*src = s;
return ((size_t)-1);
}
} else {
/*
* May not be enough space; use temp. buffer.
*/
if ((nb = _UTF8_wcrtomb(buf, *s, ps)) == (size_t)-1) {
*src = s;
return ((size_t)-1);
}
if (nb > (int)len)
/* MB sequence for character won't fit. */
break;
memcpy(dst, buf, nb);
}
if (*s == L'\0') {
*src = NULL;
return (nbytes + nb - 1);
}
s++;
dst += nb;
len -= nb;
nbytes += nb;
}
*src = s;
return (nbytes);
}