diff options
Diffstat (limited to 'lib/unistr/u8-mbtoucr.c')
| -rw-r--r-- | lib/unistr/u8-mbtoucr.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/lib/unistr/u8-mbtoucr.c b/lib/unistr/u8-mbtoucr.c new file mode 100644 index 0000000..afc43b6 --- /dev/null +++ b/lib/unistr/u8-mbtoucr.c @@ -0,0 +1,142 @@ +/* Look at first character in UTF-8 string, returning an error code. + Copyright (C) 1999-2002, 2006-2007, 2009-2020 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2001. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include "unistr.h" + +int +u8_mbtoucr (ucs4_t *puc, const uint8_t *s, size_t n) +{ + uint8_t c = *s; + + if (c < 0x80) + { + *puc = c; + return 1; + } + else if (c >= 0xc2) + { + if (c < 0xe0) + { + if (n >= 2) + { + if ((s[1] ^ 0x80) < 0x40) + { + *puc = ((unsigned int) (c & 0x1f) << 6) + | (unsigned int) (s[1] ^ 0x80); + return 2; + } + /* invalid multibyte character */ + } + else + { + /* incomplete multibyte character */ + *puc = 0xfffd; + return -2; + } + } + else if (c < 0xf0) + { + if (n >= 2) + { + if ((s[1] ^ 0x80) < 0x40 + && (c >= 0xe1 || s[1] >= 0xa0) + && (c != 0xed || s[1] < 0xa0)) + { + if (n >= 3) + { + if ((s[2] ^ 0x80) < 0x40) + { + *puc = ((unsigned int) (c & 0x0f) << 12) + | ((unsigned int) (s[1] ^ 0x80) << 6) + | (unsigned int) (s[2] ^ 0x80); + return 3; + } + /* invalid multibyte character */ + } + else + { + /* incomplete multibyte character */ + *puc = 0xfffd; + return -2; + } + } + /* invalid multibyte character */ + } + else + { + /* incomplete multibyte character */ + *puc = 0xfffd; + return -2; + } + } + else if (c < 0xf8) + { + if (n >= 2) + { + if ((s[1] ^ 0x80) < 0x40 + && (c >= 0xf1 || s[1] >= 0x90) + && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90))) + { + if (n >= 3) + { + if ((s[2] ^ 0x80) < 0x40) + { + if (n >= 4) + { + if ((s[3] ^ 0x80) < 0x40) + { + *puc = ((unsigned int) (c & 0x07) << 18) + | ((unsigned int) (s[1] ^ 0x80) << 12) + | ((unsigned int) (s[2] ^ 0x80) << 6) + | (unsigned int) (s[3] ^ 0x80); + return 4; + } + /* invalid multibyte character */ + } + else + { + /* incomplete multibyte character */ + *puc = 0xfffd; + return -2; + } + } + /* invalid multibyte character */ + } + else + { + /* incomplete multibyte character */ + *puc = 0xfffd; + return -2; + } + } + /* invalid multibyte character */ + } + else + { + /* incomplete multibyte character */ + *puc = 0xfffd; + return -2; + } + } + } + /* invalid multibyte character */ + *puc = 0xfffd; + return -1; +} |