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