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9f806850 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
44594c2f OW |
2 | /* |
3 | * Copyright (c) 2014 SGI. | |
4 | * All rights reserved. | |
44594c2f OW |
5 | */ |
6 | ||
7 | #include "utf8n.h" | |
8 | ||
2b3d0478 | 9 | int utf8version_is_supported(const struct unicode_map *um, unsigned int version) |
44594c2f | 10 | { |
2b3d0478 | 11 | int i = um->tables->utf8agetab_size - 1; |
44594c2f | 12 | |
2b3d0478 CH |
13 | while (i >= 0 && um->tables->utf8agetab[i] != 0) { |
14 | if (version == um->tables->utf8agetab[i]) | |
44594c2f OW |
15 | return 1; |
16 | i--; | |
17 | } | |
18 | return 0; | |
19 | } | |
44594c2f OW |
20 | |
21 | /* | |
22 | * UTF-8 valid ranges. | |
23 | * | |
24 | * The UTF-8 encoding spreads the bits of a 32bit word over several | |
25 | * bytes. This table gives the ranges that can be held and how they'd | |
26 | * be represented. | |
27 | * | |
28 | * 0x00000000 0x0000007F: 0xxxxxxx | |
29 | * 0x00000000 0x000007FF: 110xxxxx 10xxxxxx | |
30 | * 0x00000000 0x0000FFFF: 1110xxxx 10xxxxxx 10xxxxxx | |
31 | * 0x00000000 0x001FFFFF: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx | |
32 | * 0x00000000 0x03FFFFFF: 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | |
33 | * 0x00000000 0x7FFFFFFF: 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | |
34 | * | |
35 | * There is an additional requirement on UTF-8, in that only the | |
36 | * shortest representation of a 32bit value is to be used. A decoder | |
37 | * must not decode sequences that do not satisfy this requirement. | |
38 | * Thus the allowed ranges have a lower bound. | |
39 | * | |
40 | * 0x00000000 0x0000007F: 0xxxxxxx | |
41 | * 0x00000080 0x000007FF: 110xxxxx 10xxxxxx | |
42 | * 0x00000800 0x0000FFFF: 1110xxxx 10xxxxxx 10xxxxxx | |
43 | * 0x00010000 0x001FFFFF: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx | |
44 | * 0x00200000 0x03FFFFFF: 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | |
45 | * 0x04000000 0x7FFFFFFF: 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | |
46 | * | |
47 | * Actual unicode characters are limited to the range 0x0 - 0x10FFFF, | |
48 | * 17 planes of 65536 values. This limits the sequences actually seen | |
49 | * even more, to just the following. | |
50 | * | |
51 | * 0 - 0x7F: 0 - 0x7F | |
52 | * 0x80 - 0x7FF: 0xC2 0x80 - 0xDF 0xBF | |
53 | * 0x800 - 0xFFFF: 0xE0 0xA0 0x80 - 0xEF 0xBF 0xBF | |
54 | * 0x10000 - 0x10FFFF: 0xF0 0x90 0x80 0x80 - 0xF4 0x8F 0xBF 0xBF | |
55 | * | |
56 | * Within those ranges the surrogates 0xD800 - 0xDFFF are not allowed. | |
57 | * | |
58 | * Note that the longest sequence seen with valid usage is 4 bytes, | |
59 | * the same a single UTF-32 character. This makes the UTF-8 | |
60 | * representation of Unicode strictly smaller than UTF-32. | |
61 | * | |
62 | * The shortest sequence requirement was introduced by: | |
63 | * Corrigendum #1: UTF-8 Shortest Form | |
64 | * It can be found here: | |
65 | * http://www.unicode.org/versions/corrigendum1.html | |
66 | * | |
67 | */ | |
68 | ||
69 | /* | |
70 | * Return the number of bytes used by the current UTF-8 sequence. | |
71 | * Assumes the input points to the first byte of a valid UTF-8 | |
72 | * sequence. | |
73 | */ | |
74 | static inline int utf8clen(const char *s) | |
75 | { | |
76 | unsigned char c = *s; | |
77 | ||
78 | return 1 + (c >= 0xC0) + (c >= 0xE0) + (c >= 0xF0); | |
79 | } | |
80 | ||
a8384c68 OW |
81 | /* |
82 | * Decode a 3-byte UTF-8 sequence. | |
83 | */ | |
84 | static unsigned int | |
85 | utf8decode3(const char *str) | |
86 | { | |
87 | unsigned int uc; | |
88 | ||
89 | uc = *str++ & 0x0F; | |
90 | uc <<= 6; | |
91 | uc |= *str++ & 0x3F; | |
92 | uc <<= 6; | |
93 | uc |= *str++ & 0x3F; | |
94 | ||
95 | return uc; | |
96 | } | |
97 | ||
98 | /* | |
99 | * Encode a 3-byte UTF-8 sequence. | |
100 | */ | |
101 | static int | |
102 | utf8encode3(char *str, unsigned int val) | |
103 | { | |
104 | str[2] = (val & 0x3F) | 0x80; | |
105 | val >>= 6; | |
106 | str[1] = (val & 0x3F) | 0x80; | |
107 | val >>= 6; | |
108 | str[0] = val | 0xE0; | |
109 | ||
110 | return 3; | |
111 | } | |
112 | ||
44594c2f OW |
113 | /* |
114 | * utf8trie_t | |
115 | * | |
116 | * A compact binary tree, used to decode UTF-8 characters. | |
117 | * | |
118 | * Internal nodes are one byte for the node itself, and up to three | |
119 | * bytes for an offset into the tree. The first byte contains the | |
120 | * following information: | |
121 | * NEXTBYTE - flag - advance to next byte if set | |
122 | * BITNUM - 3 bit field - the bit number to tested | |
123 | * OFFLEN - 2 bit field - number of bytes in the offset | |
124 | * if offlen == 0 (non-branching node) | |
125 | * RIGHTPATH - 1 bit field - set if the following node is for the | |
126 | * right-hand path (tested bit is set) | |
127 | * TRIENODE - 1 bit field - set if the following node is an internal | |
128 | * node, otherwise it is a leaf node | |
129 | * if offlen != 0 (branching node) | |
130 | * LEFTNODE - 1 bit field - set if the left-hand node is internal | |
131 | * RIGHTNODE - 1 bit field - set if the right-hand node is internal | |
132 | * | |
133 | * Due to the way utf8 works, there cannot be branching nodes with | |
134 | * NEXTBYTE set, and moreover those nodes always have a righthand | |
135 | * descendant. | |
136 | */ | |
137 | typedef const unsigned char utf8trie_t; | |
138 | #define BITNUM 0x07 | |
139 | #define NEXTBYTE 0x08 | |
140 | #define OFFLEN 0x30 | |
141 | #define OFFLEN_SHIFT 4 | |
142 | #define RIGHTPATH 0x40 | |
143 | #define TRIENODE 0x80 | |
144 | #define RIGHTNODE 0x40 | |
145 | #define LEFTNODE 0x80 | |
146 | ||
147 | /* | |
148 | * utf8leaf_t | |
149 | * | |
150 | * The leaves of the trie are embedded in the trie, and so the same | |
151 | * underlying datatype: unsigned char. | |
152 | * | |
153 | * leaf[0]: The unicode version, stored as a generation number that is | |
2b3d0478 | 154 | * an index into ->utf8agetab[]. With this we can filter code |
44594c2f OW |
155 | * points based on the unicode version in which they were |
156 | * defined. The CCC of a non-defined code point is 0. | |
157 | * leaf[1]: Canonical Combining Class. During normalization, we need | |
158 | * to do a stable sort into ascending order of all characters | |
159 | * with a non-zero CCC that occur between two characters with | |
160 | * a CCC of 0, or at the begin or end of a string. | |
161 | * The unicode standard guarantees that all CCC values are | |
162 | * between 0 and 254 inclusive, which leaves 255 available as | |
163 | * a special value. | |
164 | * Code points with CCC 0 are known as stoppers. | |
165 | * leaf[2]: Decomposition. If leaf[1] == 255, then leaf[2] is the | |
166 | * start of a NUL-terminated string that is the decomposition | |
167 | * of the character. | |
168 | * The CCC of a decomposable character is the same as the CCC | |
169 | * of the first character of its decomposition. | |
170 | * Some characters decompose as the empty string: these are | |
171 | * characters with the Default_Ignorable_Code_Point property. | |
172 | * These do affect normalization, as they all have CCC 0. | |
173 | * | |
a8384c68 OW |
174 | * The decompositions in the trie have been fully expanded, with the |
175 | * exception of Hangul syllables, which are decomposed algorithmically. | |
44594c2f OW |
176 | * |
177 | * Casefolding, if applicable, is also done using decompositions. | |
178 | * | |
179 | * The trie is constructed in such a way that leaves exist for all | |
180 | * UTF-8 sequences that match the criteria from the "UTF-8 valid | |
181 | * ranges" comment above, and only for those sequences. Therefore a | |
182 | * lookup in the trie can be used to validate the UTF-8 input. | |
183 | */ | |
184 | typedef const unsigned char utf8leaf_t; | |
185 | ||
186 | #define LEAF_GEN(LEAF) ((LEAF)[0]) | |
187 | #define LEAF_CCC(LEAF) ((LEAF)[1]) | |
188 | #define LEAF_STR(LEAF) ((const char *)((LEAF) + 2)) | |
189 | ||
190 | #define MINCCC (0) | |
191 | #define MAXCCC (254) | |
192 | #define STOPPER (0) | |
193 | #define DECOMPOSE (255) | |
194 | ||
a8384c68 OW |
195 | /* Marker for hangul syllable decomposition. */ |
196 | #define HANGUL ((char)(255)) | |
197 | /* Size of the synthesized leaf used for Hangul syllable decomposition. */ | |
198 | #define UTF8HANGULLEAF (12) | |
199 | ||
200 | /* | |
201 | * Hangul decomposition (algorithm from Section 3.12 of Unicode 6.3.0) | |
202 | * | |
203 | * AC00;<Hangul Syllable, First>;Lo;0;L;;;;;N;;;;; | |
204 | * D7A3;<Hangul Syllable, Last>;Lo;0;L;;;;;N;;;;; | |
205 | * | |
206 | * SBase = 0xAC00 | |
207 | * LBase = 0x1100 | |
208 | * VBase = 0x1161 | |
209 | * TBase = 0x11A7 | |
210 | * LCount = 19 | |
211 | * VCount = 21 | |
212 | * TCount = 28 | |
213 | * NCount = 588 (VCount * TCount) | |
214 | * SCount = 11172 (LCount * NCount) | |
215 | * | |
216 | * Decomposition: | |
217 | * SIndex = s - SBase | |
218 | * | |
219 | * LV (Canonical/Full) | |
220 | * LIndex = SIndex / NCount | |
221 | * VIndex = (Sindex % NCount) / TCount | |
222 | * LPart = LBase + LIndex | |
223 | * VPart = VBase + VIndex | |
224 | * | |
225 | * LVT (Canonical) | |
226 | * LVIndex = (SIndex / TCount) * TCount | |
227 | * TIndex = (Sindex % TCount) | |
228 | * LVPart = SBase + LVIndex | |
229 | * TPart = TBase + TIndex | |
230 | * | |
231 | * LVT (Full) | |
232 | * LIndex = SIndex / NCount | |
233 | * VIndex = (Sindex % NCount) / TCount | |
234 | * TIndex = (Sindex % TCount) | |
235 | * LPart = LBase + LIndex | |
236 | * VPart = VBase + VIndex | |
237 | * if (TIndex == 0) { | |
238 | * d = <LPart, VPart> | |
239 | * } else { | |
240 | * TPart = TBase + TIndex | |
241 | * d = <LPart, TPart, VPart> | |
242 | * } | |
243 | */ | |
244 | ||
245 | /* Constants */ | |
246 | #define SB (0xAC00) | |
247 | #define LB (0x1100) | |
248 | #define VB (0x1161) | |
249 | #define TB (0x11A7) | |
250 | #define LC (19) | |
251 | #define VC (21) | |
252 | #define TC (28) | |
253 | #define NC (VC * TC) | |
254 | #define SC (LC * NC) | |
255 | ||
256 | /* Algorithmic decomposition of hangul syllable. */ | |
257 | static utf8leaf_t * | |
258 | utf8hangul(const char *str, unsigned char *hangul) | |
259 | { | |
260 | unsigned int si; | |
261 | unsigned int li; | |
262 | unsigned int vi; | |
263 | unsigned int ti; | |
264 | unsigned char *h; | |
265 | ||
266 | /* Calculate the SI, LI, VI, and TI values. */ | |
267 | si = utf8decode3(str) - SB; | |
268 | li = si / NC; | |
269 | vi = (si % NC) / TC; | |
270 | ti = si % TC; | |
271 | ||
272 | /* Fill in base of leaf. */ | |
273 | h = hangul; | |
274 | LEAF_GEN(h) = 2; | |
275 | LEAF_CCC(h) = DECOMPOSE; | |
276 | h += 2; | |
277 | ||
278 | /* Add LPart, a 3-byte UTF-8 sequence. */ | |
279 | h += utf8encode3((char *)h, li + LB); | |
280 | ||
281 | /* Add VPart, a 3-byte UTF-8 sequence. */ | |
282 | h += utf8encode3((char *)h, vi + VB); | |
283 | ||
284 | /* Add TPart if required, also a 3-byte UTF-8 sequence. */ | |
285 | if (ti) | |
286 | h += utf8encode3((char *)h, ti + TB); | |
287 | ||
288 | /* Terminate string. */ | |
289 | h[0] = '\0'; | |
290 | ||
291 | return hangul; | |
292 | } | |
293 | ||
44594c2f OW |
294 | /* |
295 | * Use trie to scan s, touching at most len bytes. | |
296 | * Returns the leaf if one exists, NULL otherwise. | |
297 | * | |
298 | * A non-NULL return guarantees that the UTF-8 sequence starting at s | |
299 | * is well-formed and corresponds to a known unicode code point. The | |
300 | * shorthand for this will be "is valid UTF-8 unicode". | |
301 | */ | |
6ca99ce7 CH |
302 | static utf8leaf_t *utf8nlookup(const struct unicode_map *um, |
303 | enum utf8_normalization n, unsigned char *hangul, const char *s, | |
304 | size_t len) | |
44594c2f | 305 | { |
2b3d0478 | 306 | utf8trie_t *trie = um->tables->utf8data + um->ntab[n]->offset; |
44594c2f OW |
307 | int offlen; |
308 | int offset; | |
309 | int mask; | |
310 | int node; | |
311 | ||
44594c2f OW |
312 | if (len == 0) |
313 | return NULL; | |
314 | ||
44594c2f OW |
315 | node = 1; |
316 | while (node) { | |
317 | offlen = (*trie & OFFLEN) >> OFFLEN_SHIFT; | |
318 | if (*trie & NEXTBYTE) { | |
319 | if (--len == 0) | |
320 | return NULL; | |
321 | s++; | |
322 | } | |
323 | mask = 1 << (*trie & BITNUM); | |
324 | if (*s & mask) { | |
325 | /* Right leg */ | |
326 | if (offlen) { | |
327 | /* Right node at offset of trie */ | |
328 | node = (*trie & RIGHTNODE); | |
329 | offset = trie[offlen]; | |
330 | while (--offlen) { | |
331 | offset <<= 8; | |
332 | offset |= trie[offlen]; | |
333 | } | |
334 | trie += offset; | |
335 | } else if (*trie & RIGHTPATH) { | |
336 | /* Right node after this node */ | |
337 | node = (*trie & TRIENODE); | |
338 | trie++; | |
339 | } else { | |
340 | /* No right node. */ | |
a8384c68 | 341 | return NULL; |
44594c2f OW |
342 | } |
343 | } else { | |
344 | /* Left leg */ | |
345 | if (offlen) { | |
346 | /* Left node after this node. */ | |
347 | node = (*trie & LEFTNODE); | |
348 | trie += offlen + 1; | |
349 | } else if (*trie & RIGHTPATH) { | |
350 | /* No left node. */ | |
a8384c68 | 351 | return NULL; |
44594c2f OW |
352 | } else { |
353 | /* Left node after this node */ | |
354 | node = (*trie & TRIENODE); | |
355 | trie++; | |
356 | } | |
357 | } | |
358 | } | |
a8384c68 OW |
359 | /* |
360 | * Hangul decomposition is done algorithmically. These are the | |
361 | * codepoints >= 0xAC00 and <= 0xD7A3. Their UTF-8 encoding is | |
362 | * always 3 bytes long, so s has been advanced twice, and the | |
363 | * start of the sequence is at s-2. | |
364 | */ | |
365 | if (LEAF_CCC(trie) == DECOMPOSE && LEAF_STR(trie)[0] == HANGUL) | |
366 | trie = utf8hangul(s - 2, hangul); | |
44594c2f OW |
367 | return trie; |
368 | } | |
369 | ||
370 | /* | |
371 | * Use trie to scan s. | |
372 | * Returns the leaf if one exists, NULL otherwise. | |
373 | * | |
374 | * Forwards to utf8nlookup(). | |
375 | */ | |
6ca99ce7 CH |
376 | static utf8leaf_t *utf8lookup(const struct unicode_map *um, |
377 | enum utf8_normalization n, unsigned char *hangul, const char *s) | |
44594c2f | 378 | { |
6ca99ce7 | 379 | return utf8nlookup(um, n, hangul, s, (size_t)-1); |
44594c2f OW |
380 | } |
381 | ||
44594c2f OW |
382 | /* |
383 | * Length of the normalization of s, touch at most len bytes. | |
384 | * Return -1 if s is not valid UTF-8 unicode. | |
385 | */ | |
6ca99ce7 CH |
386 | ssize_t utf8nlen(const struct unicode_map *um, enum utf8_normalization n, |
387 | const char *s, size_t len) | |
44594c2f OW |
388 | { |
389 | utf8leaf_t *leaf; | |
390 | size_t ret = 0; | |
a8384c68 | 391 | unsigned char hangul[UTF8HANGULLEAF]; |
44594c2f | 392 | |
44594c2f | 393 | while (len && *s) { |
6ca99ce7 | 394 | leaf = utf8nlookup(um, n, hangul, s, len); |
44594c2f OW |
395 | if (!leaf) |
396 | return -1; | |
2b3d0478 CH |
397 | if (um->tables->utf8agetab[LEAF_GEN(leaf)] > |
398 | um->ntab[n]->maxage) | |
44594c2f OW |
399 | ret += utf8clen(s); |
400 | else if (LEAF_CCC(leaf) == DECOMPOSE) | |
401 | ret += strlen(LEAF_STR(leaf)); | |
402 | else | |
403 | ret += utf8clen(s); | |
404 | len -= utf8clen(s); | |
405 | s += utf8clen(s); | |
406 | } | |
407 | return ret; | |
408 | } | |
44594c2f OW |
409 | |
410 | /* | |
411 | * Set up an utf8cursor for use by utf8byte(). | |
412 | * | |
413 | * u8c : pointer to cursor. | |
414 | * data : const struct utf8data to use for normalization. | |
415 | * s : string. | |
416 | * len : length of s. | |
417 | * | |
418 | * Returns -1 on error, 0 on success. | |
419 | */ | |
6ca99ce7 CH |
420 | int utf8ncursor(struct utf8cursor *u8c, const struct unicode_map *um, |
421 | enum utf8_normalization n, const char *s, size_t len) | |
44594c2f | 422 | { |
44594c2f OW |
423 | if (!s) |
424 | return -1; | |
6ca99ce7 CH |
425 | u8c->um = um; |
426 | u8c->n = n; | |
44594c2f OW |
427 | u8c->s = s; |
428 | u8c->p = NULL; | |
429 | u8c->ss = NULL; | |
430 | u8c->sp = NULL; | |
431 | u8c->len = len; | |
432 | u8c->slen = 0; | |
433 | u8c->ccc = STOPPER; | |
434 | u8c->nccc = STOPPER; | |
435 | /* Check we didn't clobber the maximum length. */ | |
436 | if (u8c->len != len) | |
437 | return -1; | |
438 | /* The first byte of s may not be an utf8 continuation. */ | |
439 | if (len > 0 && (*s & 0xC0) == 0x80) | |
440 | return -1; | |
441 | return 0; | |
442 | } | |
44594c2f | 443 | |
44594c2f OW |
444 | /* |
445 | * Get one byte from the normalized form of the string described by u8c. | |
446 | * | |
447 | * Returns the byte cast to an unsigned char on succes, and -1 on failure. | |
448 | * | |
449 | * The cursor keeps track of the location in the string in u8c->s. | |
450 | * When a character is decomposed, the current location is stored in | |
451 | * u8c->p, and u8c->s is set to the start of the decomposition. Note | |
452 | * that bytes from a decomposition do not count against u8c->len. | |
453 | * | |
454 | * Characters are emitted if they match the current CCC in u8c->ccc. | |
455 | * Hitting end-of-string while u8c->ccc == STOPPER means we're done, | |
456 | * and the function returns 0 in that case. | |
457 | * | |
458 | * Sorting by CCC is done by repeatedly scanning the string. The | |
459 | * values of u8c->s and u8c->p are stored in u8c->ss and u8c->sp at | |
460 | * the start of the scan. The first pass finds the lowest CCC to be | |
461 | * emitted and stores it in u8c->nccc, the second pass emits the | |
462 | * characters with this CCC and finds the next lowest CCC. This limits | |
463 | * the number of passes to 1 + the number of different CCCs in the | |
464 | * sequence being scanned. | |
465 | * | |
466 | * Therefore: | |
467 | * u8c->p != NULL -> a decomposition is being scanned. | |
468 | * u8c->ss != NULL -> this is a repeating scan. | |
469 | * u8c->ccc == -1 -> this is the first scan of a repeating scan. | |
470 | */ | |
471 | int utf8byte(struct utf8cursor *u8c) | |
472 | { | |
473 | utf8leaf_t *leaf; | |
474 | int ccc; | |
475 | ||
476 | for (;;) { | |
477 | /* Check for the end of a decomposed character. */ | |
478 | if (u8c->p && *u8c->s == '\0') { | |
479 | u8c->s = u8c->p; | |
480 | u8c->p = NULL; | |
481 | } | |
482 | ||
483 | /* Check for end-of-string. */ | |
484 | if (!u8c->p && (u8c->len == 0 || *u8c->s == '\0')) { | |
485 | /* There is no next byte. */ | |
486 | if (u8c->ccc == STOPPER) | |
487 | return 0; | |
488 | /* End-of-string during a scan counts as a stopper. */ | |
489 | ccc = STOPPER; | |
490 | goto ccc_mismatch; | |
491 | } else if ((*u8c->s & 0xC0) == 0x80) { | |
492 | /* This is a continuation of the current character. */ | |
493 | if (!u8c->p) | |
494 | u8c->len--; | |
495 | return (unsigned char)*u8c->s++; | |
496 | } | |
497 | ||
498 | /* Look up the data for the current character. */ | |
a8384c68 | 499 | if (u8c->p) { |
6ca99ce7 | 500 | leaf = utf8lookup(u8c->um, u8c->n, u8c->hangul, u8c->s); |
a8384c68 | 501 | } else { |
6ca99ce7 | 502 | leaf = utf8nlookup(u8c->um, u8c->n, u8c->hangul, |
a8384c68 OW |
503 | u8c->s, u8c->len); |
504 | } | |
44594c2f OW |
505 | |
506 | /* No leaf found implies that the input is a binary blob. */ | |
507 | if (!leaf) | |
508 | return -1; | |
509 | ||
510 | ccc = LEAF_CCC(leaf); | |
511 | /* Characters that are too new have CCC 0. */ | |
2b3d0478 | 512 | if (u8c->um->tables->utf8agetab[LEAF_GEN(leaf)] > |
6ca99ce7 | 513 | u8c->um->ntab[u8c->n]->maxage) { |
44594c2f OW |
514 | ccc = STOPPER; |
515 | } else if (ccc == DECOMPOSE) { | |
516 | u8c->len -= utf8clen(u8c->s); | |
517 | u8c->p = u8c->s + utf8clen(u8c->s); | |
518 | u8c->s = LEAF_STR(leaf); | |
519 | /* Empty decomposition implies CCC 0. */ | |
520 | if (*u8c->s == '\0') { | |
521 | if (u8c->ccc == STOPPER) | |
522 | continue; | |
523 | ccc = STOPPER; | |
524 | goto ccc_mismatch; | |
525 | } | |
a8384c68 | 526 | |
6ca99ce7 | 527 | leaf = utf8lookup(u8c->um, u8c->n, u8c->hangul, u8c->s); |
15f0d8d0 TT |
528 | if (!leaf) |
529 | return -1; | |
a8384c68 | 530 | ccc = LEAF_CCC(leaf); |
44594c2f OW |
531 | } |
532 | ||
533 | /* | |
534 | * If this is not a stopper, then see if it updates | |
535 | * the next canonical class to be emitted. | |
536 | */ | |
537 | if (ccc != STOPPER && u8c->ccc < ccc && ccc < u8c->nccc) | |
538 | u8c->nccc = ccc; | |
539 | ||
540 | /* | |
541 | * Return the current byte if this is the current | |
542 | * combining class. | |
543 | */ | |
544 | if (ccc == u8c->ccc) { | |
545 | if (!u8c->p) | |
546 | u8c->len--; | |
547 | return (unsigned char)*u8c->s++; | |
548 | } | |
549 | ||
550 | /* Current combining class mismatch. */ | |
551 | ccc_mismatch: | |
552 | if (u8c->nccc == STOPPER) { | |
553 | /* | |
554 | * Scan forward for the first canonical class | |
555 | * to be emitted. Save the position from | |
556 | * which to restart. | |
557 | */ | |
558 | u8c->ccc = MINCCC - 1; | |
559 | u8c->nccc = ccc; | |
560 | u8c->sp = u8c->p; | |
561 | u8c->ss = u8c->s; | |
562 | u8c->slen = u8c->len; | |
563 | if (!u8c->p) | |
564 | u8c->len -= utf8clen(u8c->s); | |
565 | u8c->s += utf8clen(u8c->s); | |
566 | } else if (ccc != STOPPER) { | |
567 | /* Not a stopper, and not the ccc we're emitting. */ | |
568 | if (!u8c->p) | |
569 | u8c->len -= utf8clen(u8c->s); | |
570 | u8c->s += utf8clen(u8c->s); | |
571 | } else if (u8c->nccc != MAXCCC + 1) { | |
572 | /* At a stopper, restart for next ccc. */ | |
573 | u8c->ccc = u8c->nccc; | |
574 | u8c->nccc = MAXCCC + 1; | |
575 | u8c->s = u8c->ss; | |
576 | u8c->p = u8c->sp; | |
577 | u8c->len = u8c->slen; | |
578 | } else { | |
579 | /* All done, proceed from here. */ | |
580 | u8c->ccc = STOPPER; | |
581 | u8c->nccc = STOPPER; | |
582 | u8c->sp = NULL; | |
583 | u8c->ss = NULL; | |
584 | u8c->slen = 0; | |
585 | } | |
586 | } | |
587 | } | |
e2a58d2d CH |
588 | |
589 | #ifdef CONFIG_UNICODE_NORMALIZATION_SELFTEST_MODULE | |
590 | EXPORT_SYMBOL_GPL(utf8version_is_supported); | |
591 | EXPORT_SYMBOL_GPL(utf8nlen); | |
592 | EXPORT_SYMBOL_GPL(utf8ncursor); | |
593 | EXPORT_SYMBOL_GPL(utf8byte); | |
594 | #endif |