67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/* Conversion UCS-4 to UTF-8.
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Copyright (C) 2002, 2006-2007, 2009-2020 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 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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#ifndef FALLTHROUGH
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# if __GNUC__ < 7
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# define FALLTHROUGH ((void) 0)
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# else
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# define FALLTHROUGH __attribute__ ((__fallthrough__))
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# endif
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#endif
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int
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u8_uctomb_aux (uint8_t *s, ucs4_t uc, int n)
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{
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int count;
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if (uc < 0x80)
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/* The case n >= 1 is already handled by the caller. */
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return -2;
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else if (uc < 0x800)
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count = 2;
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else if (uc < 0x10000)
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{
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if (uc < 0xd800 || uc >= 0xe000)
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count = 3;
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else
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return -1;
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}
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else if (uc < 0x110000)
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count = 4;
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else
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return -1;
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if (n < count)
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return -2;
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switch (count) /* note: code falls through cases! */
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{
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case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;
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FALLTHROUGH;
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case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;
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FALLTHROUGH;
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case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;
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/*case 1:*/ s[0] = uc;
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}
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return count;
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}
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