diff options
Diffstat (limited to 'lib/libc/locale/utf8.c')
-rw-r--r-- | lib/libc/locale/utf8.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/lib/libc/locale/utf8.c b/lib/libc/locale/utf8.c new file mode 100644 index 0000000..e467fc0 --- /dev/null +++ b/lib/libc/locale/utf8.c @@ -0,0 +1,421 @@ +/*- + * 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" + +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; + + 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); +} |