106 lines
3.0 KiB
C
106 lines
3.0 KiB
C
/* Check UTF-8 string.
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Copyright (C) 2002, 2006-2007, 2009-2015 Free Software Foundation, Inc.
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Written by Bruno Haible <bruno@clisp.org>, 2002.
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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 Lesser General Public License as published
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by the Free Software Foundation; either version 2.1 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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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <http://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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const uint8_t *
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u8_check (const uint8_t *s, size_t n)
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{
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const uint8_t *s_end = s + n;
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while (s < s_end)
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{
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/* Keep in sync with unistr.h and u8-mbtouc-aux.c. */
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uint8_t c = *s;
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if (c < 0x80)
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{
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s++;
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continue;
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}
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if (c >= 0xc2)
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{
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if (c < 0xe0)
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{
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if (s + 2 <= s_end
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&& (s[1] ^ 0x80) < 0x40)
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{
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s += 2;
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continue;
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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 (s + 3 <= s_end
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&& (s[1] ^ 0x80) < 0x40 && (s[2] ^ 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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s += 3;
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continue;
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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 (s + 4 <= s_end
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&& (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
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&& (s[3] ^ 0x80) < 0x40
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&& (c >= 0xf1 || s[1] >= 0x90)
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#if 1
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&& (c < 0xf4 || (c == 0xf4 && s[1] < 0x90))
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#endif
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)
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{
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s += 4;
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continue;
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}
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}
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#if 0
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else if (c < 0xfc)
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{
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if (s + 5 <= s_end
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&& (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
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&& (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
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&& (c >= 0xf9 || s[1] >= 0x88))
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{
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s += 5;
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continue;
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}
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}
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else if (c < 0xfe)
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{
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if (s + 6 <= s_end
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&& (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
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&& (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
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&& (s[5] ^ 0x80) < 0x40
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&& (c >= 0xfd || s[1] >= 0x84))
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{
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s += 6;
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continue;
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}
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}
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#endif
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}
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/* invalid or incomplete multibyte character */
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return s;
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}
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return NULL;
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}
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