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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 */
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