rm_/lib/mbrtowc-impl-utf8.h

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/* Convert multibyte character to wide character.
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Copyright (C) 1999-2002, 2005-2022 Free Software Foundation, Inc.
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This file 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 2.1 of the
License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU 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 <https://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2008. */
/* This file contains the part of the body of the mbrtowc and mbrtoc32 functions
that handles the special case of the UTF-8 encoding. */
/* Cf. unistr/u8-mbtouc.c. */
unsigned char c = (unsigned char) p[0];
if (c < 0x80)
{
if (pwc != NULL)
*pwc = c;
res = (c == 0 ? 0 : 1);
goto success;
}
if (c >= 0xc2)
{
if (c < 0xe0)
{
if (m == 1)
goto incomplete;
else /* m >= 2 */
{
unsigned char c2 = (unsigned char) p[1];
if ((c2 ^ 0x80) < 0x40)
{
if (pwc != NULL)
*pwc = ((unsigned int) (c & 0x1f) << 6)
| (unsigned int) (c2 ^ 0x80);
res = 2;
goto success;
}
}
}
else if (c < 0xf0)
{
if (m == 1)
goto incomplete;
else
{
unsigned char c2 = (unsigned char) p[1];
if ((c2 ^ 0x80) < 0x40
&& (c >= 0xe1 || c2 >= 0xa0)
&& (c != 0xed || c2 < 0xa0))
{
if (m == 2)
goto incomplete;
else /* m >= 3 */
{
unsigned char c3 = (unsigned char) p[2];
if ((c3 ^ 0x80) < 0x40)
{
unsigned int wc =
(((unsigned int) (c & 0x0f) << 12)
| ((unsigned int) (c2 ^ 0x80) << 6)
| (unsigned int) (c3 ^ 0x80));
if (FITS_IN_CHAR_TYPE (wc))
{
if (pwc != NULL)
*pwc = wc;
res = 3;
goto success;
}
}
}
}
}
}
else if (c <= 0xf4)
{
if (m == 1)
goto incomplete;
else
{
unsigned char c2 = (unsigned char) p[1];
if ((c2 ^ 0x80) < 0x40
&& (c >= 0xf1 || c2 >= 0x90)
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&& (c < 0xf4 || (/* c == 0xf4 && */ c2 < 0x90)))
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{
if (m == 2)
goto incomplete;
else
{
unsigned char c3 = (unsigned char) p[2];
if ((c3 ^ 0x80) < 0x40)
{
if (m == 3)
goto incomplete;
else /* m >= 4 */
{
unsigned char c4 = (unsigned char) p[3];
if ((c4 ^ 0x80) < 0x40)
{
unsigned int wc =
(((unsigned int) (c & 0x07) << 18)
| ((unsigned int) (c2 ^ 0x80) << 12)
| ((unsigned int) (c3 ^ 0x80) << 6)
| (unsigned int) (c4 ^ 0x80));
if (FITS_IN_CHAR_TYPE (wc))
{
if (pwc != NULL)
*pwc = wc;
res = 4;
goto success;
}
}
}
}
}
}
}
}
}
goto invalid;