fs/unicode/utf8n.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (c) 2014 SGI.
   4  * All rights reserved.
   5  */
   6
   7 #ifndef UTF8NORM_H
   8 #define UTF8NORM_H
   9
  10 #include <linux/types.h>
  11 #include <linux/export.h>
  12 #include <linux/string.h>
  13 #include <linux/module.h>
  14
  15 /* Encoding a unicode version number as a single unsigned int. */
  16 #define UNICODE_MAJ_SHIFT               (16)
  17 #define UNICODE_MIN_SHIFT               (8)
  18
  19 #define UNICODE_AGE(MAJ, MIN, REV)                      \
  20         (((unsigned int)(MAJ) << UNICODE_MAJ_SHIFT) |   \
  21          ((unsigned int)(MIN) << UNICODE_MIN_SHIFT) |   \
  22          ((unsigned int)(REV)))
  23
  24 /* Highest unicode version supported by the data tables. */
  25 extern int utf8version_is_supported(u8 maj, u8 min, u8 rev);
  26 extern int utf8version_latest(void);
  27
  28 /*
  29  * Look for the correct const struct utf8data for a unicode version.
  30  * Returns NULL if the version requested is too new.
  31  *
  32  * Two normalization forms are supported: nfdi and nfdicf.
  33  *
  34  * nfdi:
  35  *  - Apply unicode normalization form NFD.
  36  *  - Remove any Default_Ignorable_Code_Point.
  37  *
  38  * nfdicf:
  39  *  - Apply unicode normalization form NFD.
  40  *  - Remove any Default_Ignorable_Code_Point.
  41  *  - Apply a full casefold (C + F).
  42  */
  43 extern const struct utf8data *utf8nfdi(unsigned int maxage);
  44 extern const struct utf8data *utf8nfdicf(unsigned int maxage);
  45
  46 /*
  47  * Determine the maximum age of any unicode character in the string.
  48  * Returns 0 if only unassigned code points are present.
  49  * Returns -1 if the input is not valid UTF-8.
  50  */
  51 extern int utf8agemax(const struct utf8data *data, const char *s);
  52 extern int utf8nagemax(const struct utf8data *data, const char *s, size_t len);
  53
  54 /*
  55  * Determine the minimum age of any unicode character in the string.
  56  * Returns 0 if any unassigned code points are present.
  57  * Returns -1 if the input is not valid UTF-8.
  58  */
  59 extern int utf8agemin(const struct utf8data *data, const char *s);
  60 extern int utf8nagemin(const struct utf8data *data, const char *s, size_t len);
  61
  62 /*
  63  * Determine the length of the normalized from of the string,
  64  * excluding any terminating NULL byte.
  65  * Returns 0 if only ignorable code points are present.
  66  * Returns -1 if the input is not valid UTF-8.
  67  */
  68 extern ssize_t utf8len(const struct utf8data *data, const char *s);
  69 extern ssize_t utf8nlen(const struct utf8data *data, const char *s, size_t len);
  70
  71 /* Needed in struct utf8cursor below. */
  72 #define UTF8HANGULLEAF  (12)
  73
  74 /*
  75  * Cursor structure used by the normalizer.
  76  */
  77 struct utf8cursor {
  78         const struct utf8data   *data;
  79         const char      *s;
  80         const char      *p;
  81         const char      *ss;
  82         const char      *sp;
  83         unsigned int    len;
  84         unsigned int    slen;
  85         short int       ccc;
  86         short int       nccc;
  87         unsigned char   hangul[UTF8HANGULLEAF];
  88 };
  89
  90 /*
  91  * Initialize a utf8cursor to normalize a string.
  92  * Returns 0 on success.
  93  * Returns -1 on failure.
  94  */
  95 extern int utf8cursor(struct utf8cursor *u8c, const struct utf8data *data,
  96                       const char *s);
  97 extern int utf8ncursor(struct utf8cursor *u8c, const struct utf8data *data,
  98                        const char *s, size_t len);
  99
 100 /*
 101  * Get the next byte in the normalization.
 102  * Returns a value > 0 && < 256 on success.
 103  * Returns 0 when the end of the normalization is reached.
 104  * Returns -1 if the string being normalized is not valid UTF-8.
 105  */
 106 extern int utf8byte(struct utf8cursor *u8c);
 107
 108 #endif /* UTF8NORM_H */