/*
* UTF-16
*/
/* Here we accept FFFE/FEFF marks as endianness indicators everywhere
in the stream, not just at the beginning. The default is big-endian. */
/* The state is 0 if big-endian, 1 if little-endian. */
static int
utf16_mbtowc (conv_t conv, wchar_t *pwc, const unsigned char *s, int n)
{
state_t state = conv->istate;
int count = 0;
for (; n >= 2;) {
wchar_t wc = (state ? s[0] + (s[1] << 8) : (s[0] << 8) + s[1]);
if (wc == 0xfeff) {
} else if (wc == 0xfffe) {
state ^= 1;
} else if (wc >= 0xd800 && wc < 0xdc00) {
if (n >= 4) {
wchar_t wc2 = (state ? s[2] + (s[3] << 8) : (s[2] << 8) + s[3]);
if (!(wc2 >= 0xdc00 && wc2 < 0xe000))
return RET_ILSEQ;
*pwc = 0x10000 + ((wc - 0xd800) << 10) + (wc2 - 0xdc00);
conv->istate = state;
return count+4;
} else
break;
} else if (wc >= 0xdc00 && wc < 0xe000) {
return RET_ILSEQ;
} else {
*pwc = wc;
conv->istate = state;
return count+2;
}
s += 2; n -= 2; count += 2;
}
conv->istate = state;
return RET_TOOFEW(count);
}
/* But we output UTF-16 in big-endian order, without byte-order mark. */
static int
utf16_wctomb (conv_t conv, unsigned char *r, wchar_t wc, int n)
{
if (wc != 0xfffe) {
if (wc < 0x10000) {
if (n >= 2) {
r[0] = (unsigned char) (wc >> 8);
r[1] = (unsigned char) wc;
return 2;
} else
return RET_TOOSMALL;
}
else if (wc < 0x110000) {
if (n >= 4) {
wchar_t wc1 = 0xd800 + ((wc - 0x10000) >> 10);
wchar_t wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
r[0] = (unsigned char) (wc1 >> 8);
r[1] = (unsigned char) wc1;
r[2] = (unsigned char) (wc2 >> 8);
r[3] = (unsigned char) wc2;
return 4;
} else
return RET_TOOSMALL;
}
}
return RET_ILSEQ;
}
