/*
* Copyright (C) 1999-2001 Free Software Foundation, Inc.
* This file is part of the GNU LIBICONV Library.
*
* The GNU LIBICONV Library is free software; you can redistribute it
* and/or modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* The GNU LIBICONV Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with the GNU LIBICONV Library; see the file COPYING.LIB.
* If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
* Fifth Floor, Boston, MA 02110-1301, USA.
*/
/*
* UTF-32
*/
/* Specification: Unicode 3.1 Standard Annex #19 */
/* Here we accept FFFE0000/0000FEFF marks as endianness indicators
everywhere in the stream, not just at the beginning. (This is contrary
to what #19 D36c specifies, but it allows concatenation of byte
sequences to work flawlessly, while disagreeing with #19 behaviour
only for strings containing U+FEFF characters, which is quite rare.)
The default is big-endian. */
/* The state is 0 if big-endian, 1 if little-endian. */
static int
utf32_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
{
state_t state = conv->istate;
int count = 0;
for (; n >= 4;) {
ucs4_t wc = (state
? s[0] + (s[1] << 8) + (s[2] << 16) + (s[3] << 24)
: (s[0] << 24) + (s[1] << 16) + (s[2] << 8) + s[3]);
count += 4;
if (wc == 0x0000feff) {
} else if (wc == 0xfffe0000u) {
state ^= 1;
} else {
if (wc < 0x110000 && !(wc >= 0xd800 && wc < 0xe000)) {
*pwc = wc;
conv->istate = state;
return count;
} else
return RET_ILSEQ;
}
s += 4; n -= 4;
}
conv->istate = state;
return RET_TOOFEW(count);
}
/* We output UTF-32 in big-endian order, with byte-order mark. */
/* The state is 0 at the beginning, 1 after the BOM has been written. */
static int
utf32_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
{
if (wc < 0x110000 && !(wc >= 0xd800 && wc < 0xe000)) {
int count = 0;
if (!conv->ostate) {
if (n >= 4) {
r[0] = 0x00;
r[1] = 0x00;
r[2] = 0xFE;
r[3] = 0xFF;
r += 4; n -= 4; count += 4;
} else
return RET_TOOSMALL;
}
if (wc < 0x110000) {
if (n >= 4) {
r[0] = 0;
r[1] = (unsigned char) (wc >> 16);
r[2] = (unsigned char) (wc >> 8);
r[3] = (unsigned char) wc;
conv->ostate = 1;
return count+4;
} else
return RET_TOOSMALL;
}
}
return RET_ILUNI;
}
