xref: /openbmc/linux/fs/unicode/utf8n.h (revision 6ca99ce756c27852d1ea1e555045de1c920f30ed)
19f806850SThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-only */
244594c2fSOlaf Weber /*
344594c2fSOlaf Weber  * Copyright (c) 2014 SGI.
444594c2fSOlaf Weber  * All rights reserved.
544594c2fSOlaf Weber  */
644594c2fSOlaf Weber 
744594c2fSOlaf Weber #ifndef UTF8NORM_H
844594c2fSOlaf Weber #define UTF8NORM_H
944594c2fSOlaf Weber 
1044594c2fSOlaf Weber #include <linux/types.h>
1144594c2fSOlaf Weber #include <linux/export.h>
1244594c2fSOlaf Weber #include <linux/string.h>
1344594c2fSOlaf Weber #include <linux/module.h>
1449bd03ccSChristoph Hellwig #include <linux/unicode.h>
1544594c2fSOlaf Weber 
1649bd03ccSChristoph Hellwig int utf8version_is_supported(unsigned int version);
1744594c2fSOlaf Weber 
1844594c2fSOlaf Weber /*
1944594c2fSOlaf Weber  * Look for the correct const struct utf8data for a unicode version.
2044594c2fSOlaf Weber  * Returns NULL if the version requested is too new.
2144594c2fSOlaf Weber  *
2244594c2fSOlaf Weber  * Two normalization forms are supported: nfdi and nfdicf.
2344594c2fSOlaf Weber  *
2444594c2fSOlaf Weber  * nfdi:
2544594c2fSOlaf Weber  *  - Apply unicode normalization form NFD.
2644594c2fSOlaf Weber  *  - Remove any Default_Ignorable_Code_Point.
2744594c2fSOlaf Weber  *
2844594c2fSOlaf Weber  * nfdicf:
2944594c2fSOlaf Weber  *  - Apply unicode normalization form NFD.
3044594c2fSOlaf Weber  *  - Remove any Default_Ignorable_Code_Point.
3144594c2fSOlaf Weber  *  - Apply a full casefold (C + F).
3244594c2fSOlaf Weber  */
3344594c2fSOlaf Weber extern const struct utf8data *utf8nfdi(unsigned int maxage);
3444594c2fSOlaf Weber extern const struct utf8data *utf8nfdicf(unsigned int maxage);
3544594c2fSOlaf Weber 
3644594c2fSOlaf Weber /*
3744594c2fSOlaf Weber  * Determine the length of the normalized from of the string,
3844594c2fSOlaf Weber  * excluding any terminating NULL byte.
3944594c2fSOlaf Weber  * Returns 0 if only ignorable code points are present.
4044594c2fSOlaf Weber  * Returns -1 if the input is not valid UTF-8.
4144594c2fSOlaf Weber  */
42*6ca99ce7SChristoph Hellwig ssize_t utf8nlen(const struct unicode_map *um, enum utf8_normalization n,
43*6ca99ce7SChristoph Hellwig 		const char *s, size_t len);
4444594c2fSOlaf Weber 
45a8384c68SOlaf Weber /* Needed in struct utf8cursor below. */
46a8384c68SOlaf Weber #define UTF8HANGULLEAF	(12)
47a8384c68SOlaf Weber 
4844594c2fSOlaf Weber /*
4944594c2fSOlaf Weber  * Cursor structure used by the normalizer.
5044594c2fSOlaf Weber  */
5144594c2fSOlaf Weber struct utf8cursor {
52*6ca99ce7SChristoph Hellwig 	const struct unicode_map *um;
53*6ca99ce7SChristoph Hellwig 	enum utf8_normalization n;
5444594c2fSOlaf Weber 	const char	*s;
5544594c2fSOlaf Weber 	const char	*p;
5644594c2fSOlaf Weber 	const char	*ss;
5744594c2fSOlaf Weber 	const char	*sp;
5844594c2fSOlaf Weber 	unsigned int	len;
5944594c2fSOlaf Weber 	unsigned int	slen;
6044594c2fSOlaf Weber 	short int	ccc;
6144594c2fSOlaf Weber 	short int	nccc;
62a8384c68SOlaf Weber 	unsigned char	hangul[UTF8HANGULLEAF];
6344594c2fSOlaf Weber };
6444594c2fSOlaf Weber 
6544594c2fSOlaf Weber /*
6644594c2fSOlaf Weber  * Initialize a utf8cursor to normalize a string.
6744594c2fSOlaf Weber  * Returns 0 on success.
6844594c2fSOlaf Weber  * Returns -1 on failure.
6944594c2fSOlaf Weber  */
70*6ca99ce7SChristoph Hellwig int utf8ncursor(struct utf8cursor *u8c, const struct unicode_map *um,
71*6ca99ce7SChristoph Hellwig 		enum utf8_normalization n, const char *s, size_t len);
7244594c2fSOlaf Weber 
7344594c2fSOlaf Weber /*
7444594c2fSOlaf Weber  * Get the next byte in the normalization.
7544594c2fSOlaf Weber  * Returns a value > 0 && < 256 on success.
7644594c2fSOlaf Weber  * Returns 0 when the end of the normalization is reached.
7744594c2fSOlaf Weber  * Returns -1 if the string being normalized is not valid UTF-8.
7844594c2fSOlaf Weber  */
7944594c2fSOlaf Weber extern int utf8byte(struct utf8cursor *u8c);
8044594c2fSOlaf Weber 
8144594c2fSOlaf Weber #endif /* UTF8NORM_H */
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