diff options
Diffstat (limited to 'lib/unistr/u8-strmbtouc.c')
| -rw-r--r-- | lib/unistr/u8-strmbtouc.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/lib/unistr/u8-strmbtouc.c b/lib/unistr/u8-strmbtouc.c new file mode 100644 index 00000000..bc2fdb0d --- /dev/null +++ b/lib/unistr/u8-strmbtouc.c @@ -0,0 +1,129 @@ +/* Look at first character in UTF-8 string. + Copyright (C) 1999-2000, 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" + +int +u8_strmbtouc (ucs4_t *puc, const uint8_t *s) +{ + /* Keep in sync with unistr.h and utf8-ucs4.c. */ + uint8_t c = *s; + + if (c < 0x80) + { + *puc = c; + return (c != 0 ? 1 : 0); + } + if (c >= 0xc2) + { + if (c < 0xe0) + { +#if CONFIG_UNICODE_SAFETY + if ((s[1] ^ 0x80) < 0x40) +#else + if (s[1] != 0) +#endif + { + *puc = ((unsigned int) (c & 0x1f) << 6) + | (unsigned int) (s[1] ^ 0x80); + return 2; + } + } + else if (c < 0xf0) + { +#if CONFIG_UNICODE_SAFETY + if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 + && (c >= 0xe1 || s[1] >= 0xa0) + && (c != 0xed || s[1] < 0xa0)) +#else + if (s[1] != 0 && s[2] != 0) +#endif + { + *puc = ((unsigned int) (c & 0x0f) << 12) + | ((unsigned int) (s[1] ^ 0x80) << 6) + | (unsigned int) (s[2] ^ 0x80); + return 3; + } + } + else if (c < 0xf8) + { +#if CONFIG_UNICODE_SAFETY + if ((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 + ) +#else + if (s[1] != 0 && s[2] != 0 && s[3] != 0) +#endif + { + *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; + } + } +#if 0 + else if (c < 0xfc) + { +#if CONFIG_UNICODE_SAFETY + if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 + && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40 + && (c >= 0xf9 || s[1] >= 0x88)) +#else + if (s[1] != 0 && s[2] != 0 && s[3] != 0 && s[4] != 0) +#endif + { + *puc = ((unsigned int) (c & 0x03) << 24) + | ((unsigned int) (s[1] ^ 0x80) << 18) + | ((unsigned int) (s[2] ^ 0x80) << 12) + | ((unsigned int) (s[3] ^ 0x80) << 6) + | (unsigned int) (s[4] ^ 0x80); + return 5; + } + } + else if (c < 0xfe) + { +#if CONFIG_UNICODE_SAFETY + if ((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)) +#else + if (s[1] != 0 && s[2] != 0 && s[3] != 0 && s[4] != 0 && s[5] != 0) +#endif + { + *puc = ((unsigned int) (c & 0x01) << 30) + | ((unsigned int) (s[1] ^ 0x80) << 24) + | ((unsigned int) (s[2] ^ 0x80) << 18) + | ((unsigned int) (s[3] ^ 0x80) << 12) + | ((unsigned int) (s[4] ^ 0x80) << 6) + | (unsigned int) (s[5] ^ 0x80); + return 6; + } + } +#endif + } + /* invalid or incomplete multibyte character */ + return -1; +} |