839b115309
Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: Gabriel Krisman Bertazi <krisman@collabora.com>
801 lines
20 KiB
C
801 lines
20 KiB
C
/*
|
|
* Copyright (c) 2014 SGI.
|
|
* All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
*/
|
|
|
|
#include "utf8n.h"
|
|
|
|
struct utf8data {
|
|
unsigned int maxage;
|
|
unsigned int offset;
|
|
};
|
|
|
|
#define __INCLUDED_FROM_UTF8NORM_C__
|
|
#include "utf8data.h"
|
|
#undef __INCLUDED_FROM_UTF8NORM_C__
|
|
|
|
int utf8version_is_supported(u8 maj, u8 min, u8 rev)
|
|
{
|
|
int i = ARRAY_SIZE(utf8agetab) - 1;
|
|
unsigned int sb_utf8version = UNICODE_AGE(maj, min, rev);
|
|
|
|
while (i >= 0 && utf8agetab[i] != 0) {
|
|
if (sb_utf8version == utf8agetab[i])
|
|
return 1;
|
|
i--;
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(utf8version_is_supported);
|
|
|
|
int utf8version_latest(void)
|
|
{
|
|
return utf8vers;
|
|
}
|
|
EXPORT_SYMBOL(utf8version_latest);
|
|
|
|
/*
|
|
* UTF-8 valid ranges.
|
|
*
|
|
* The UTF-8 encoding spreads the bits of a 32bit word over several
|
|
* bytes. This table gives the ranges that can be held and how they'd
|
|
* be represented.
|
|
*
|
|
* 0x00000000 0x0000007F: 0xxxxxxx
|
|
* 0x00000000 0x000007FF: 110xxxxx 10xxxxxx
|
|
* 0x00000000 0x0000FFFF: 1110xxxx 10xxxxxx 10xxxxxx
|
|
* 0x00000000 0x001FFFFF: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
* 0x00000000 0x03FFFFFF: 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
* 0x00000000 0x7FFFFFFF: 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
*
|
|
* There is an additional requirement on UTF-8, in that only the
|
|
* shortest representation of a 32bit value is to be used. A decoder
|
|
* must not decode sequences that do not satisfy this requirement.
|
|
* Thus the allowed ranges have a lower bound.
|
|
*
|
|
* 0x00000000 0x0000007F: 0xxxxxxx
|
|
* 0x00000080 0x000007FF: 110xxxxx 10xxxxxx
|
|
* 0x00000800 0x0000FFFF: 1110xxxx 10xxxxxx 10xxxxxx
|
|
* 0x00010000 0x001FFFFF: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
* 0x00200000 0x03FFFFFF: 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
* 0x04000000 0x7FFFFFFF: 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
*
|
|
* Actual unicode characters are limited to the range 0x0 - 0x10FFFF,
|
|
* 17 planes of 65536 values. This limits the sequences actually seen
|
|
* even more, to just the following.
|
|
*
|
|
* 0 - 0x7F: 0 - 0x7F
|
|
* 0x80 - 0x7FF: 0xC2 0x80 - 0xDF 0xBF
|
|
* 0x800 - 0xFFFF: 0xE0 0xA0 0x80 - 0xEF 0xBF 0xBF
|
|
* 0x10000 - 0x10FFFF: 0xF0 0x90 0x80 0x80 - 0xF4 0x8F 0xBF 0xBF
|
|
*
|
|
* Within those ranges the surrogates 0xD800 - 0xDFFF are not allowed.
|
|
*
|
|
* Note that the longest sequence seen with valid usage is 4 bytes,
|
|
* the same a single UTF-32 character. This makes the UTF-8
|
|
* representation of Unicode strictly smaller than UTF-32.
|
|
*
|
|
* The shortest sequence requirement was introduced by:
|
|
* Corrigendum #1: UTF-8 Shortest Form
|
|
* It can be found here:
|
|
* http://www.unicode.org/versions/corrigendum1.html
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Return the number of bytes used by the current UTF-8 sequence.
|
|
* Assumes the input points to the first byte of a valid UTF-8
|
|
* sequence.
|
|
*/
|
|
static inline int utf8clen(const char *s)
|
|
{
|
|
unsigned char c = *s;
|
|
|
|
return 1 + (c >= 0xC0) + (c >= 0xE0) + (c >= 0xF0);
|
|
}
|
|
|
|
/*
|
|
* Decode a 3-byte UTF-8 sequence.
|
|
*/
|
|
static unsigned int
|
|
utf8decode3(const char *str)
|
|
{
|
|
unsigned int uc;
|
|
|
|
uc = *str++ & 0x0F;
|
|
uc <<= 6;
|
|
uc |= *str++ & 0x3F;
|
|
uc <<= 6;
|
|
uc |= *str++ & 0x3F;
|
|
|
|
return uc;
|
|
}
|
|
|
|
/*
|
|
* Encode a 3-byte UTF-8 sequence.
|
|
*/
|
|
static int
|
|
utf8encode3(char *str, unsigned int val)
|
|
{
|
|
str[2] = (val & 0x3F) | 0x80;
|
|
val >>= 6;
|
|
str[1] = (val & 0x3F) | 0x80;
|
|
val >>= 6;
|
|
str[0] = val | 0xE0;
|
|
|
|
return 3;
|
|
}
|
|
|
|
/*
|
|
* utf8trie_t
|
|
*
|
|
* A compact binary tree, used to decode UTF-8 characters.
|
|
*
|
|
* Internal nodes are one byte for the node itself, and up to three
|
|
* bytes for an offset into the tree. The first byte contains the
|
|
* following information:
|
|
* NEXTBYTE - flag - advance to next byte if set
|
|
* BITNUM - 3 bit field - the bit number to tested
|
|
* OFFLEN - 2 bit field - number of bytes in the offset
|
|
* if offlen == 0 (non-branching node)
|
|
* RIGHTPATH - 1 bit field - set if the following node is for the
|
|
* right-hand path (tested bit is set)
|
|
* TRIENODE - 1 bit field - set if the following node is an internal
|
|
* node, otherwise it is a leaf node
|
|
* if offlen != 0 (branching node)
|
|
* LEFTNODE - 1 bit field - set if the left-hand node is internal
|
|
* RIGHTNODE - 1 bit field - set if the right-hand node is internal
|
|
*
|
|
* Due to the way utf8 works, there cannot be branching nodes with
|
|
* NEXTBYTE set, and moreover those nodes always have a righthand
|
|
* descendant.
|
|
*/
|
|
typedef const unsigned char utf8trie_t;
|
|
#define BITNUM 0x07
|
|
#define NEXTBYTE 0x08
|
|
#define OFFLEN 0x30
|
|
#define OFFLEN_SHIFT 4
|
|
#define RIGHTPATH 0x40
|
|
#define TRIENODE 0x80
|
|
#define RIGHTNODE 0x40
|
|
#define LEFTNODE 0x80
|
|
|
|
/*
|
|
* utf8leaf_t
|
|
*
|
|
* The leaves of the trie are embedded in the trie, and so the same
|
|
* underlying datatype: unsigned char.
|
|
*
|
|
* leaf[0]: The unicode version, stored as a generation number that is
|
|
* an index into utf8agetab[]. With this we can filter code
|
|
* points based on the unicode version in which they were
|
|
* defined. The CCC of a non-defined code point is 0.
|
|
* leaf[1]: Canonical Combining Class. During normalization, we need
|
|
* to do a stable sort into ascending order of all characters
|
|
* with a non-zero CCC that occur between two characters with
|
|
* a CCC of 0, or at the begin or end of a string.
|
|
* The unicode standard guarantees that all CCC values are
|
|
* between 0 and 254 inclusive, which leaves 255 available as
|
|
* a special value.
|
|
* Code points with CCC 0 are known as stoppers.
|
|
* leaf[2]: Decomposition. If leaf[1] == 255, then leaf[2] is the
|
|
* start of a NUL-terminated string that is the decomposition
|
|
* of the character.
|
|
* The CCC of a decomposable character is the same as the CCC
|
|
* of the first character of its decomposition.
|
|
* Some characters decompose as the empty string: these are
|
|
* characters with the Default_Ignorable_Code_Point property.
|
|
* These do affect normalization, as they all have CCC 0.
|
|
*
|
|
* The decompositions in the trie have been fully expanded, with the
|
|
* exception of Hangul syllables, which are decomposed algorithmically.
|
|
*
|
|
* Casefolding, if applicable, is also done using decompositions.
|
|
*
|
|
* The trie is constructed in such a way that leaves exist for all
|
|
* UTF-8 sequences that match the criteria from the "UTF-8 valid
|
|
* ranges" comment above, and only for those sequences. Therefore a
|
|
* lookup in the trie can be used to validate the UTF-8 input.
|
|
*/
|
|
typedef const unsigned char utf8leaf_t;
|
|
|
|
#define LEAF_GEN(LEAF) ((LEAF)[0])
|
|
#define LEAF_CCC(LEAF) ((LEAF)[1])
|
|
#define LEAF_STR(LEAF) ((const char *)((LEAF) + 2))
|
|
|
|
#define MINCCC (0)
|
|
#define MAXCCC (254)
|
|
#define STOPPER (0)
|
|
#define DECOMPOSE (255)
|
|
|
|
/* Marker for hangul syllable decomposition. */
|
|
#define HANGUL ((char)(255))
|
|
/* Size of the synthesized leaf used for Hangul syllable decomposition. */
|
|
#define UTF8HANGULLEAF (12)
|
|
|
|
/*
|
|
* Hangul decomposition (algorithm from Section 3.12 of Unicode 6.3.0)
|
|
*
|
|
* AC00;<Hangul Syllable, First>;Lo;0;L;;;;;N;;;;;
|
|
* D7A3;<Hangul Syllable, Last>;Lo;0;L;;;;;N;;;;;
|
|
*
|
|
* SBase = 0xAC00
|
|
* LBase = 0x1100
|
|
* VBase = 0x1161
|
|
* TBase = 0x11A7
|
|
* LCount = 19
|
|
* VCount = 21
|
|
* TCount = 28
|
|
* NCount = 588 (VCount * TCount)
|
|
* SCount = 11172 (LCount * NCount)
|
|
*
|
|
* Decomposition:
|
|
* SIndex = s - SBase
|
|
*
|
|
* LV (Canonical/Full)
|
|
* LIndex = SIndex / NCount
|
|
* VIndex = (Sindex % NCount) / TCount
|
|
* LPart = LBase + LIndex
|
|
* VPart = VBase + VIndex
|
|
*
|
|
* LVT (Canonical)
|
|
* LVIndex = (SIndex / TCount) * TCount
|
|
* TIndex = (Sindex % TCount)
|
|
* LVPart = SBase + LVIndex
|
|
* TPart = TBase + TIndex
|
|
*
|
|
* LVT (Full)
|
|
* LIndex = SIndex / NCount
|
|
* VIndex = (Sindex % NCount) / TCount
|
|
* TIndex = (Sindex % TCount)
|
|
* LPart = LBase + LIndex
|
|
* VPart = VBase + VIndex
|
|
* if (TIndex == 0) {
|
|
* d = <LPart, VPart>
|
|
* } else {
|
|
* TPart = TBase + TIndex
|
|
* d = <LPart, TPart, VPart>
|
|
* }
|
|
*/
|
|
|
|
/* Constants */
|
|
#define SB (0xAC00)
|
|
#define LB (0x1100)
|
|
#define VB (0x1161)
|
|
#define TB (0x11A7)
|
|
#define LC (19)
|
|
#define VC (21)
|
|
#define TC (28)
|
|
#define NC (VC * TC)
|
|
#define SC (LC * NC)
|
|
|
|
/* Algorithmic decomposition of hangul syllable. */
|
|
static utf8leaf_t *
|
|
utf8hangul(const char *str, unsigned char *hangul)
|
|
{
|
|
unsigned int si;
|
|
unsigned int li;
|
|
unsigned int vi;
|
|
unsigned int ti;
|
|
unsigned char *h;
|
|
|
|
/* Calculate the SI, LI, VI, and TI values. */
|
|
si = utf8decode3(str) - SB;
|
|
li = si / NC;
|
|
vi = (si % NC) / TC;
|
|
ti = si % TC;
|
|
|
|
/* Fill in base of leaf. */
|
|
h = hangul;
|
|
LEAF_GEN(h) = 2;
|
|
LEAF_CCC(h) = DECOMPOSE;
|
|
h += 2;
|
|
|
|
/* Add LPart, a 3-byte UTF-8 sequence. */
|
|
h += utf8encode3((char *)h, li + LB);
|
|
|
|
/* Add VPart, a 3-byte UTF-8 sequence. */
|
|
h += utf8encode3((char *)h, vi + VB);
|
|
|
|
/* Add TPart if required, also a 3-byte UTF-8 sequence. */
|
|
if (ti)
|
|
h += utf8encode3((char *)h, ti + TB);
|
|
|
|
/* Terminate string. */
|
|
h[0] = '\0';
|
|
|
|
return hangul;
|
|
}
|
|
|
|
/*
|
|
* Use trie to scan s, touching at most len bytes.
|
|
* Returns the leaf if one exists, NULL otherwise.
|
|
*
|
|
* A non-NULL return guarantees that the UTF-8 sequence starting at s
|
|
* is well-formed and corresponds to a known unicode code point. The
|
|
* shorthand for this will be "is valid UTF-8 unicode".
|
|
*/
|
|
static utf8leaf_t *utf8nlookup(const struct utf8data *data,
|
|
unsigned char *hangul, const char *s, size_t len)
|
|
{
|
|
utf8trie_t *trie = NULL;
|
|
int offlen;
|
|
int offset;
|
|
int mask;
|
|
int node;
|
|
|
|
if (!data)
|
|
return NULL;
|
|
if (len == 0)
|
|
return NULL;
|
|
|
|
trie = utf8data + data->offset;
|
|
node = 1;
|
|
while (node) {
|
|
offlen = (*trie & OFFLEN) >> OFFLEN_SHIFT;
|
|
if (*trie & NEXTBYTE) {
|
|
if (--len == 0)
|
|
return NULL;
|
|
s++;
|
|
}
|
|
mask = 1 << (*trie & BITNUM);
|
|
if (*s & mask) {
|
|
/* Right leg */
|
|
if (offlen) {
|
|
/* Right node at offset of trie */
|
|
node = (*trie & RIGHTNODE);
|
|
offset = trie[offlen];
|
|
while (--offlen) {
|
|
offset <<= 8;
|
|
offset |= trie[offlen];
|
|
}
|
|
trie += offset;
|
|
} else if (*trie & RIGHTPATH) {
|
|
/* Right node after this node */
|
|
node = (*trie & TRIENODE);
|
|
trie++;
|
|
} else {
|
|
/* No right node. */
|
|
return NULL;
|
|
}
|
|
} else {
|
|
/* Left leg */
|
|
if (offlen) {
|
|
/* Left node after this node. */
|
|
node = (*trie & LEFTNODE);
|
|
trie += offlen + 1;
|
|
} else if (*trie & RIGHTPATH) {
|
|
/* No left node. */
|
|
return NULL;
|
|
} else {
|
|
/* Left node after this node */
|
|
node = (*trie & TRIENODE);
|
|
trie++;
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* Hangul decomposition is done algorithmically. These are the
|
|
* codepoints >= 0xAC00 and <= 0xD7A3. Their UTF-8 encoding is
|
|
* always 3 bytes long, so s has been advanced twice, and the
|
|
* start of the sequence is at s-2.
|
|
*/
|
|
if (LEAF_CCC(trie) == DECOMPOSE && LEAF_STR(trie)[0] == HANGUL)
|
|
trie = utf8hangul(s - 2, hangul);
|
|
return trie;
|
|
}
|
|
|
|
/*
|
|
* Use trie to scan s.
|
|
* Returns the leaf if one exists, NULL otherwise.
|
|
*
|
|
* Forwards to utf8nlookup().
|
|
*/
|
|
static utf8leaf_t *utf8lookup(const struct utf8data *data,
|
|
unsigned char *hangul, const char *s)
|
|
{
|
|
return utf8nlookup(data, hangul, s, (size_t)-1);
|
|
}
|
|
|
|
/*
|
|
* Maximum age of any character in s.
|
|
* Return -1 if s is not valid UTF-8 unicode.
|
|
* Return 0 if only non-assigned code points are used.
|
|
*/
|
|
int utf8agemax(const struct utf8data *data, const char *s)
|
|
{
|
|
utf8leaf_t *leaf;
|
|
int age = 0;
|
|
int leaf_age;
|
|
unsigned char hangul[UTF8HANGULLEAF];
|
|
|
|
if (!data)
|
|
return -1;
|
|
|
|
while (*s) {
|
|
leaf = utf8lookup(data, hangul, s);
|
|
if (!leaf)
|
|
return -1;
|
|
|
|
leaf_age = utf8agetab[LEAF_GEN(leaf)];
|
|
if (leaf_age <= data->maxage && leaf_age > age)
|
|
age = leaf_age;
|
|
s += utf8clen(s);
|
|
}
|
|
return age;
|
|
}
|
|
EXPORT_SYMBOL(utf8agemax);
|
|
|
|
/*
|
|
* Minimum age of any character in s.
|
|
* Return -1 if s is not valid UTF-8 unicode.
|
|
* Return 0 if non-assigned code points are used.
|
|
*/
|
|
int utf8agemin(const struct utf8data *data, const char *s)
|
|
{
|
|
utf8leaf_t *leaf;
|
|
int age;
|
|
int leaf_age;
|
|
unsigned char hangul[UTF8HANGULLEAF];
|
|
|
|
if (!data)
|
|
return -1;
|
|
age = data->maxage;
|
|
while (*s) {
|
|
leaf = utf8lookup(data, hangul, s);
|
|
if (!leaf)
|
|
return -1;
|
|
leaf_age = utf8agetab[LEAF_GEN(leaf)];
|
|
if (leaf_age <= data->maxage && leaf_age < age)
|
|
age = leaf_age;
|
|
s += utf8clen(s);
|
|
}
|
|
return age;
|
|
}
|
|
EXPORT_SYMBOL(utf8agemin);
|
|
|
|
/*
|
|
* Maximum age of any character in s, touch at most len bytes.
|
|
* Return -1 if s is not valid UTF-8 unicode.
|
|
*/
|
|
int utf8nagemax(const struct utf8data *data, const char *s, size_t len)
|
|
{
|
|
utf8leaf_t *leaf;
|
|
int age = 0;
|
|
int leaf_age;
|
|
unsigned char hangul[UTF8HANGULLEAF];
|
|
|
|
if (!data)
|
|
return -1;
|
|
|
|
while (len && *s) {
|
|
leaf = utf8nlookup(data, hangul, s, len);
|
|
if (!leaf)
|
|
return -1;
|
|
leaf_age = utf8agetab[LEAF_GEN(leaf)];
|
|
if (leaf_age <= data->maxage && leaf_age > age)
|
|
age = leaf_age;
|
|
len -= utf8clen(s);
|
|
s += utf8clen(s);
|
|
}
|
|
return age;
|
|
}
|
|
EXPORT_SYMBOL(utf8nagemax);
|
|
|
|
/*
|
|
* Maximum age of any character in s, touch at most len bytes.
|
|
* Return -1 if s is not valid UTF-8 unicode.
|
|
*/
|
|
int utf8nagemin(const struct utf8data *data, const char *s, size_t len)
|
|
{
|
|
utf8leaf_t *leaf;
|
|
int leaf_age;
|
|
int age;
|
|
unsigned char hangul[UTF8HANGULLEAF];
|
|
|
|
if (!data)
|
|
return -1;
|
|
age = data->maxage;
|
|
while (len && *s) {
|
|
leaf = utf8nlookup(data, hangul, s, len);
|
|
if (!leaf)
|
|
return -1;
|
|
leaf_age = utf8agetab[LEAF_GEN(leaf)];
|
|
if (leaf_age <= data->maxage && leaf_age < age)
|
|
age = leaf_age;
|
|
len -= utf8clen(s);
|
|
s += utf8clen(s);
|
|
}
|
|
return age;
|
|
}
|
|
EXPORT_SYMBOL(utf8nagemin);
|
|
|
|
/*
|
|
* Length of the normalization of s.
|
|
* Return -1 if s is not valid UTF-8 unicode.
|
|
*
|
|
* A string of Default_Ignorable_Code_Point has length 0.
|
|
*/
|
|
ssize_t utf8len(const struct utf8data *data, const char *s)
|
|
{
|
|
utf8leaf_t *leaf;
|
|
size_t ret = 0;
|
|
unsigned char hangul[UTF8HANGULLEAF];
|
|
|
|
if (!data)
|
|
return -1;
|
|
while (*s) {
|
|
leaf = utf8lookup(data, hangul, s);
|
|
if (!leaf)
|
|
return -1;
|
|
if (utf8agetab[LEAF_GEN(leaf)] > data->maxage)
|
|
ret += utf8clen(s);
|
|
else if (LEAF_CCC(leaf) == DECOMPOSE)
|
|
ret += strlen(LEAF_STR(leaf));
|
|
else
|
|
ret += utf8clen(s);
|
|
s += utf8clen(s);
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(utf8len);
|
|
|
|
/*
|
|
* Length of the normalization of s, touch at most len bytes.
|
|
* Return -1 if s is not valid UTF-8 unicode.
|
|
*/
|
|
ssize_t utf8nlen(const struct utf8data *data, const char *s, size_t len)
|
|
{
|
|
utf8leaf_t *leaf;
|
|
size_t ret = 0;
|
|
unsigned char hangul[UTF8HANGULLEAF];
|
|
|
|
if (!data)
|
|
return -1;
|
|
while (len && *s) {
|
|
leaf = utf8nlookup(data, hangul, s, len);
|
|
if (!leaf)
|
|
return -1;
|
|
if (utf8agetab[LEAF_GEN(leaf)] > data->maxage)
|
|
ret += utf8clen(s);
|
|
else if (LEAF_CCC(leaf) == DECOMPOSE)
|
|
ret += strlen(LEAF_STR(leaf));
|
|
else
|
|
ret += utf8clen(s);
|
|
len -= utf8clen(s);
|
|
s += utf8clen(s);
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(utf8nlen);
|
|
|
|
/*
|
|
* Set up an utf8cursor for use by utf8byte().
|
|
*
|
|
* u8c : pointer to cursor.
|
|
* data : const struct utf8data to use for normalization.
|
|
* s : string.
|
|
* len : length of s.
|
|
*
|
|
* Returns -1 on error, 0 on success.
|
|
*/
|
|
int utf8ncursor(struct utf8cursor *u8c, const struct utf8data *data,
|
|
const char *s, size_t len)
|
|
{
|
|
if (!data)
|
|
return -1;
|
|
if (!s)
|
|
return -1;
|
|
u8c->data = data;
|
|
u8c->s = s;
|
|
u8c->p = NULL;
|
|
u8c->ss = NULL;
|
|
u8c->sp = NULL;
|
|
u8c->len = len;
|
|
u8c->slen = 0;
|
|
u8c->ccc = STOPPER;
|
|
u8c->nccc = STOPPER;
|
|
/* Check we didn't clobber the maximum length. */
|
|
if (u8c->len != len)
|
|
return -1;
|
|
/* The first byte of s may not be an utf8 continuation. */
|
|
if (len > 0 && (*s & 0xC0) == 0x80)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(utf8ncursor);
|
|
|
|
/*
|
|
* Set up an utf8cursor for use by utf8byte().
|
|
*
|
|
* u8c : pointer to cursor.
|
|
* data : const struct utf8data to use for normalization.
|
|
* s : NUL-terminated string.
|
|
*
|
|
* Returns -1 on error, 0 on success.
|
|
*/
|
|
int utf8cursor(struct utf8cursor *u8c, const struct utf8data *data,
|
|
const char *s)
|
|
{
|
|
return utf8ncursor(u8c, data, s, (unsigned int)-1);
|
|
}
|
|
EXPORT_SYMBOL(utf8cursor);
|
|
|
|
/*
|
|
* Get one byte from the normalized form of the string described by u8c.
|
|
*
|
|
* Returns the byte cast to an unsigned char on succes, and -1 on failure.
|
|
*
|
|
* The cursor keeps track of the location in the string in u8c->s.
|
|
* When a character is decomposed, the current location is stored in
|
|
* u8c->p, and u8c->s is set to the start of the decomposition. Note
|
|
* that bytes from a decomposition do not count against u8c->len.
|
|
*
|
|
* Characters are emitted if they match the current CCC in u8c->ccc.
|
|
* Hitting end-of-string while u8c->ccc == STOPPER means we're done,
|
|
* and the function returns 0 in that case.
|
|
*
|
|
* Sorting by CCC is done by repeatedly scanning the string. The
|
|
* values of u8c->s and u8c->p are stored in u8c->ss and u8c->sp at
|
|
* the start of the scan. The first pass finds the lowest CCC to be
|
|
* emitted and stores it in u8c->nccc, the second pass emits the
|
|
* characters with this CCC and finds the next lowest CCC. This limits
|
|
* the number of passes to 1 + the number of different CCCs in the
|
|
* sequence being scanned.
|
|
*
|
|
* Therefore:
|
|
* u8c->p != NULL -> a decomposition is being scanned.
|
|
* u8c->ss != NULL -> this is a repeating scan.
|
|
* u8c->ccc == -1 -> this is the first scan of a repeating scan.
|
|
*/
|
|
int utf8byte(struct utf8cursor *u8c)
|
|
{
|
|
utf8leaf_t *leaf;
|
|
int ccc;
|
|
|
|
for (;;) {
|
|
/* Check for the end of a decomposed character. */
|
|
if (u8c->p && *u8c->s == '\0') {
|
|
u8c->s = u8c->p;
|
|
u8c->p = NULL;
|
|
}
|
|
|
|
/* Check for end-of-string. */
|
|
if (!u8c->p && (u8c->len == 0 || *u8c->s == '\0')) {
|
|
/* There is no next byte. */
|
|
if (u8c->ccc == STOPPER)
|
|
return 0;
|
|
/* End-of-string during a scan counts as a stopper. */
|
|
ccc = STOPPER;
|
|
goto ccc_mismatch;
|
|
} else if ((*u8c->s & 0xC0) == 0x80) {
|
|
/* This is a continuation of the current character. */
|
|
if (!u8c->p)
|
|
u8c->len--;
|
|
return (unsigned char)*u8c->s++;
|
|
}
|
|
|
|
/* Look up the data for the current character. */
|
|
if (u8c->p) {
|
|
leaf = utf8lookup(u8c->data, u8c->hangul, u8c->s);
|
|
} else {
|
|
leaf = utf8nlookup(u8c->data, u8c->hangul,
|
|
u8c->s, u8c->len);
|
|
}
|
|
|
|
/* No leaf found implies that the input is a binary blob. */
|
|
if (!leaf)
|
|
return -1;
|
|
|
|
ccc = LEAF_CCC(leaf);
|
|
/* Characters that are too new have CCC 0. */
|
|
if (utf8agetab[LEAF_GEN(leaf)] > u8c->data->maxage) {
|
|
ccc = STOPPER;
|
|
} else if (ccc == DECOMPOSE) {
|
|
u8c->len -= utf8clen(u8c->s);
|
|
u8c->p = u8c->s + utf8clen(u8c->s);
|
|
u8c->s = LEAF_STR(leaf);
|
|
/* Empty decomposition implies CCC 0. */
|
|
if (*u8c->s == '\0') {
|
|
if (u8c->ccc == STOPPER)
|
|
continue;
|
|
ccc = STOPPER;
|
|
goto ccc_mismatch;
|
|
}
|
|
|
|
leaf = utf8lookup(u8c->data, u8c->hangul, u8c->s);
|
|
if (!leaf)
|
|
return -1;
|
|
ccc = LEAF_CCC(leaf);
|
|
}
|
|
|
|
/*
|
|
* If this is not a stopper, then see if it updates
|
|
* the next canonical class to be emitted.
|
|
*/
|
|
if (ccc != STOPPER && u8c->ccc < ccc && ccc < u8c->nccc)
|
|
u8c->nccc = ccc;
|
|
|
|
/*
|
|
* Return the current byte if this is the current
|
|
* combining class.
|
|
*/
|
|
if (ccc == u8c->ccc) {
|
|
if (!u8c->p)
|
|
u8c->len--;
|
|
return (unsigned char)*u8c->s++;
|
|
}
|
|
|
|
/* Current combining class mismatch. */
|
|
ccc_mismatch:
|
|
if (u8c->nccc == STOPPER) {
|
|
/*
|
|
* Scan forward for the first canonical class
|
|
* to be emitted. Save the position from
|
|
* which to restart.
|
|
*/
|
|
u8c->ccc = MINCCC - 1;
|
|
u8c->nccc = ccc;
|
|
u8c->sp = u8c->p;
|
|
u8c->ss = u8c->s;
|
|
u8c->slen = u8c->len;
|
|
if (!u8c->p)
|
|
u8c->len -= utf8clen(u8c->s);
|
|
u8c->s += utf8clen(u8c->s);
|
|
} else if (ccc != STOPPER) {
|
|
/* Not a stopper, and not the ccc we're emitting. */
|
|
if (!u8c->p)
|
|
u8c->len -= utf8clen(u8c->s);
|
|
u8c->s += utf8clen(u8c->s);
|
|
} else if (u8c->nccc != MAXCCC + 1) {
|
|
/* At a stopper, restart for next ccc. */
|
|
u8c->ccc = u8c->nccc;
|
|
u8c->nccc = MAXCCC + 1;
|
|
u8c->s = u8c->ss;
|
|
u8c->p = u8c->sp;
|
|
u8c->len = u8c->slen;
|
|
} else {
|
|
/* All done, proceed from here. */
|
|
u8c->ccc = STOPPER;
|
|
u8c->nccc = STOPPER;
|
|
u8c->sp = NULL;
|
|
u8c->ss = NULL;
|
|
u8c->slen = 0;
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(utf8byte);
|
|
|
|
const struct utf8data *utf8nfdi(unsigned int maxage)
|
|
{
|
|
int i = ARRAY_SIZE(utf8nfdidata) - 1;
|
|
|
|
while (maxage < utf8nfdidata[i].maxage)
|
|
i--;
|
|
if (maxage > utf8nfdidata[i].maxage)
|
|
return NULL;
|
|
return &utf8nfdidata[i];
|
|
}
|
|
EXPORT_SYMBOL(utf8nfdi);
|
|
|
|
const struct utf8data *utf8nfdicf(unsigned int maxage)
|
|
{
|
|
int i = ARRAY_SIZE(utf8nfdicfdata) - 1;
|
|
|
|
while (maxage < utf8nfdicfdata[i].maxage)
|
|
i--;
|
|
if (maxage > utf8nfdicfdata[i].maxage)
|
|
return NULL;
|
|
return &utf8nfdicfdata[i];
|
|
}
|
|
EXPORT_SYMBOL(utf8nfdicf);
|