diff options
Diffstat (limited to 'lib/unistr/u8-check.c')
-rw-r--r-- | lib/unistr/u8-check.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/lib/unistr/u8-check.c b/lib/unistr/u8-check.c new file mode 100644 index 0000000..53897fc --- /dev/null +++ b/lib/unistr/u8-check.c @@ -0,0 +1,105 @@ +/* Check UTF-8 string. + Copyright (C) 2002, 2006-2007 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2002. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU Lesser 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include "unistr.h" + +const uint8_t * +u8_check (const uint8_t *s, size_t n) +{ + const uint8_t *s_end = s + n; + + while (s < s_end) + { + /* Keep in sync with unistr.h and utf8-ucs4.c. */ + uint8_t c = *s; + + if (c < 0x80) + { + s++; + continue; + } + if (c >= 0xc2) + { + if (c < 0xe0) + { + if (s + 2 <= s_end + && (s[1] ^ 0x80) < 0x40) + { + s += 2; + continue; + } + } + else if (c < 0xf0) + { + if (s + 3 <= s_end + && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 + && (c >= 0xe1 || s[1] >= 0xa0) + && (c != 0xed || s[1] < 0xa0)) + { + s += 3; + continue; + } + } + else if (c < 0xf8) + { + if (s + 4 <= s_end + && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 + && (s[3] ^ 0x80) < 0x40 + && (c >= 0xf1 || s[1] >= 0x90) +#if 1 + && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90)) +#endif + ) + { + s += 4; + continue; + } + } +#if 0 + else if (c < 0xfc) + { + if (s + 5 <= s_end + && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 + && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40 + && (c >= 0xf9 || s[1] >= 0x88)) + { + s += 5; + continue; + } + } + else if (c < 0xfe) + { + if (s + 6 <= s_end + && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 + && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40 + && (s[5] ^ 0x80) < 0x40 + && (c >= 0xfd || s[1] >= 0x84)) + { + s += 6; + continue; + } + } +#endif + } + /* invalid or incomplete multibyte character */ + return s; + } + return NULL; +} |