utf.h
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#ifndef _LINUX_UTF_H
#define _LINUX_UTF_H
#include <asm/unaligned.h>
static inline int utf8_to_utf16le(const char *s, __le16 *cp, unsigned len)
{
int count = 0;
u8 c;
u16 uchar;
/*
* this insists on correct encodings, though not minimal ones.
* BUT it currently rejects legit 4-byte UTF-8 code points,
* which need surrogate pairs. (Unicode 3.1 can use them.)
*/
while (len != 0 && (c = (u8) *s++) != 0) {
if ((c & 0x80)) {
/*
* 2-byte sequence:
* 00000yyyyyxxxxxx = 110yyyyy 10xxxxxx
*/
if ((c & 0xe0) == 0xc0) {
uchar = (c & 0x1f) << 6;
c = (u8) *s++;
if ((c & 0xc0) != 0x80)
goto fail;
c &= 0x3f;
uchar |= c;
/*
* 3-byte sequence (most CJKV characters):
* zzzzyyyyyyxxxxxx = 1110zzzz 10yyyyyy 10xxxxxx
*/
} else if ((c & 0xf0) == 0xe0) {
uchar = (c & 0x0f) << 12;
c = (u8) *s++;
if ((c & 0xc0) != 0x80)
goto fail;
c &= 0x3f;
uchar |= c << 6;
c = (u8) *s++;
if ((c & 0xc0) != 0x80)
goto fail;
c &= 0x3f;
uchar |= c;
/* no bogus surrogates */
if (0xd800 <= uchar && uchar <= 0xdfff)
goto fail;
/*
* 4-byte sequence (surrogate pairs, currently rare):
* 11101110wwwwzzzzyy + 110111yyyyxxxxxx
* = 11110uuu 10uuzzzz 10yyyyyy 10xxxxxx
* (uuuuu = wwww + 1)
* FIXME accept the surrogate code points (only)
*/
} else
goto fail;
} else
uchar = c;
put_unaligned_le16(uchar, cp++);
count++;
len--;
}
return count;
fail:
return -1;
}
#endif /* _LINUX_UTF_H */