| 1 | /* kwset.c - search for any of a set of keywords. |
| 2 | Copyright 1989 Free Software Foundation |
| 3 | Written August 1989 by Mike Haertel. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 1, or (at your option) |
| 8 | any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, write to the Free Software |
| 17 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 18 | |
| 19 | The author may be reached (Email) at the address mike@ai.mit.edu, |
| 20 | or (US mail) as Mike Haertel c/o Free Software Foundation. */ |
| 21 | |
| 22 | #include "std.h" |
| 23 | |
| 24 | /* The algorithm implemented by these routines bears a startling resemblence |
| 25 | to one discovered by Beate Commentz-Walter, although it is not identical. |
| 26 | See "A String Matching Algorithm Fast on the Average," Technical Report, |
| 27 | IBM-Germany, Scientific Center Heidelberg, Tiergartenstrasse 15, D-6900 |
| 28 | Heidelberg, Germany. See also Aho, A.V., and M. Corasick, "Efficient |
| 29 | String Matching: An Aid to Bibliographic Search," CACM June 1975, |
| 30 | Vol. 18, No. 6, which describes the failure function used below. */ |
| 31 | |
| 32 | #include "kwset.h" |
| 33 | #include "obstack.h" |
| 34 | |
| 35 | #define NCHAR (UCHAR_MAX + 1) |
| 36 | #define obstack_chunk_alloc malloc |
| 37 | #define obstack_chunk_free free |
| 38 | |
| 39 | /* Balanced tree of edges and labels leaving a given trie node. */ |
| 40 | struct tree |
| 41 | { |
| 42 | struct tree *llink; /* Left link; MUST be first field. */ |
| 43 | struct tree *rlink; /* Right link (to larger labels). */ |
| 44 | struct trie *trie; /* Trie node pointed to by this edge. */ |
| 45 | unsigned char label; /* Label on this edge. */ |
| 46 | char balance; /* Difference in depths of subtrees. */ |
| 47 | }; |
| 48 | |
| 49 | /* Node of a trie representing a set of reversed keywords. */ |
| 50 | struct trie |
| 51 | { |
| 52 | unsigned int accepting; /* Word index of accepted word, or zero. */ |
| 53 | struct tree *links; /* Tree of edges leaving this node. */ |
| 54 | struct trie *parent; /* Parent of this node. */ |
| 55 | struct trie *next; /* List of all trie nodes in level order. */ |
| 56 | struct trie *fail; /* Aho-Corasick failure function. */ |
| 57 | int depth; /* Depth of this node from the root. */ |
| 58 | int shift; /* Shift function for search failures. */ |
| 59 | int maxshift; /* Max shift of self and descendents. */ |
| 60 | }; |
| 61 | |
| 62 | /* Structure returned opaquely to the caller, containing everything. */ |
| 63 | struct kwset |
| 64 | { |
| 65 | struct obstack obstack; /* Obstack for node allocation. */ |
| 66 | int words; /* Number of words in the trie. */ |
| 67 | struct trie *trie; /* The trie itself. */ |
| 68 | int mind; /* Minimum depth of an accepting node. */ |
| 69 | int maxd; /* Maximum depth of any node. */ |
| 70 | int delta[NCHAR]; /* Delta table for rapid search. */ |
| 71 | struct trie *next[NCHAR]; /* Table of children of the root. */ |
| 72 | const char *trans; /* Character translation table. */ |
| 73 | }; |
| 74 | |
| 75 | /* Allocate and initialize a keyword set object, returning an opaque |
| 76 | pointer to it. Return NULL if memory is not available. */ |
| 77 | kwset_t |
| 78 | DEFUN(kwsalloc, (trans), const char *trans) |
| 79 | { |
| 80 | struct kwset *kwset; |
| 81 | |
| 82 | kwset = (struct kwset *) malloc(sizeof (struct kwset)); |
| 83 | if (!kwset) |
| 84 | return NULL; |
| 85 | |
| 86 | obstack_init(&kwset->obstack); |
| 87 | kwset->words = 0; |
| 88 | kwset->trie |
| 89 | = (struct trie *) obstack_alloc(&kwset->obstack, sizeof (struct trie)); |
| 90 | if (!kwset->trie) |
| 91 | { |
| 92 | kwsfree((kwset_t) kwset); |
| 93 | return NULL; |
| 94 | } |
| 95 | kwset->trie->accepting = 0; |
| 96 | kwset->trie->links = NULL; |
| 97 | kwset->trie->parent = NULL; |
| 98 | kwset->trie->next = NULL; |
| 99 | kwset->trie->fail = NULL; |
| 100 | kwset->trie->depth = 0; |
| 101 | kwset->trie->shift = 0; |
| 102 | kwset->mind = INT_MAX; |
| 103 | kwset->maxd = -1; |
| 104 | kwset->trans = trans; |
| 105 | |
| 106 | return (kwset_t) kwset; |
| 107 | } |
| 108 | |
| 109 | /* Add the given string to the contents of the keyword set. Return NULL |
| 110 | for success, an error message otherwise. */ |
| 111 | const char * |
| 112 | DEFUN(kwsincr, (kws, text, len), |
| 113 | kwset_t kws AND const char *text AND size_t len) |
| 114 | { |
| 115 | struct kwset *kwset; |
| 116 | register struct trie *trie; |
| 117 | register unsigned char label; |
| 118 | register struct tree *link; |
| 119 | register int depth; |
| 120 | struct tree *links[12]; |
| 121 | enum { L, R } dirs[12]; |
| 122 | struct tree *t, *r, *l, *rl, *lr; |
| 123 | |
| 124 | kwset = (struct kwset *) kws; |
| 125 | trie = kwset->trie; |
| 126 | text += len; |
| 127 | |
| 128 | /* Descend the trie (built of reversed keywords) character-by-character, |
| 129 | installing new nodes when necessary. */ |
| 130 | while (len--) |
| 131 | { |
| 132 | label = kwset->trans ? kwset->trans[(unsigned char) *--text] : *--text; |
| 133 | |
| 134 | /* Descend the tree of outgoing links for this trie node, |
| 135 | looking for the current character and keeping track |
| 136 | of the path followed. */ |
| 137 | link = trie->links; |
| 138 | links[0] = (struct tree *) &trie->links; |
| 139 | dirs[0] = L; |
| 140 | depth = 1; |
| 141 | |
| 142 | while (link && label != link->label) |
| 143 | { |
| 144 | links[depth] = link; |
| 145 | if (label < link->label) |
| 146 | dirs[depth++] = L, link = link->llink; |
| 147 | else |
| 148 | dirs[depth++] = R, link = link->rlink; |
| 149 | } |
| 150 | |
| 151 | /* The current character doesn't have an outgoing link at |
| 152 | this trie node, so build a new trie node and install |
| 153 | a link in the current trie node's tree. */ |
| 154 | if (!link) |
| 155 | { |
| 156 | link = (struct tree *) obstack_alloc(&kwset->obstack, |
| 157 | sizeof (struct tree)); |
| 158 | if (!link) |
| 159 | return "memory exhausted"; |
| 160 | link->llink = NULL; |
| 161 | link->rlink = NULL; |
| 162 | link->trie = (struct trie *) obstack_alloc(&kwset->obstack, |
| 163 | sizeof (struct trie)); |
| 164 | if (!link->trie) |
| 165 | return "memory exhausted"; |
| 166 | link->trie->accepting = 0; |
| 167 | link->trie->links = NULL; |
| 168 | link->trie->parent = trie; |
| 169 | link->trie->next = NULL; |
| 170 | link->trie->fail = NULL; |
| 171 | link->trie->depth = trie->depth + 1; |
| 172 | link->trie->shift = 0; |
| 173 | link->label = label; |
| 174 | link->balance = 0; |
| 175 | |
| 176 | /* Install the new tree node in its parent. */ |
| 177 | if (dirs[--depth] == L) |
| 178 | links[depth]->llink = link; |
| 179 | else |
| 180 | links[depth]->rlink = link; |
| 181 | |
| 182 | /* Back up the tree fixing the balance flags. */ |
| 183 | while (depth && !links[depth]->balance) |
| 184 | { |
| 185 | if (dirs[depth] == L) |
| 186 | --links[depth]->balance; |
| 187 | else |
| 188 | ++links[depth]->balance; |
| 189 | --depth; |
| 190 | } |
| 191 | |
| 192 | /* Rebalance the tree by pointer rotations if necessary. */ |
| 193 | if (depth && (dirs[depth] == L && --links[depth]->balance |
| 194 | || dirs[depth] == R && ++links[depth]->balance)) |
| 195 | { |
| 196 | switch (links[depth]->balance) |
| 197 | { |
| 198 | case (char) -2: |
| 199 | switch (dirs[depth + 1]) |
| 200 | { |
| 201 | case L: |
| 202 | r = links[depth], t = r->llink, rl = t->rlink; |
| 203 | t->rlink = r, r->llink = rl; |
| 204 | t->balance = r->balance = 0; |
| 205 | break; |
| 206 | case R: |
| 207 | r = links[depth], l = r->llink, t = l->rlink; |
| 208 | rl = t->rlink, lr = t->llink; |
| 209 | t->llink = l, l->rlink = lr, t->rlink = r, r->llink = rl; |
| 210 | l->balance = t->balance != 1 ? 0 : -1; |
| 211 | r->balance = t->balance != (char) -1 ? 0 : 1; |
| 212 | t->balance = 0; |
| 213 | break; |
| 214 | } |
| 215 | break; |
| 216 | case 2: |
| 217 | switch (dirs[depth + 1]) |
| 218 | { |
| 219 | case R: |
| 220 | l = links[depth], t = l->rlink, lr = t->llink; |
| 221 | t->llink = l, l->rlink = lr; |
| 222 | t->balance = l->balance = 0; |
| 223 | break; |
| 224 | case L: |
| 225 | l = links[depth], r = l->rlink, t = r->llink; |
| 226 | lr = t->llink, rl = t->rlink; |
| 227 | t->llink = l, l->rlink = lr, t->rlink = r, r->llink = rl; |
| 228 | l->balance = t->balance != 1 ? 0 : -1; |
| 229 | r->balance = t->balance != (char) -1 ? 0 : 1; |
| 230 | t->balance = 0; |
| 231 | break; |
| 232 | } |
| 233 | break; |
| 234 | } |
| 235 | |
| 236 | if (dirs[depth - 1] == L) |
| 237 | links[depth - 1]->llink = t; |
| 238 | else |
| 239 | links[depth - 1]->rlink = t; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | trie = link->trie; |
| 244 | } |
| 245 | |
| 246 | /* Mark the node we finally reached as accepting, encoding the |
| 247 | index number of this word in the keyword set so far. */ |
| 248 | if (!trie->accepting) |
| 249 | trie->accepting = 1 + 2 * kwset->words; |
| 250 | ++kwset->words; |
| 251 | |
| 252 | /* Keep track of the longest and shortest string of the keyword set. */ |
| 253 | if (trie->depth < kwset->mind) |
| 254 | kwset->mind = trie->depth; |
| 255 | if (trie->depth > kwset->maxd) |
| 256 | kwset->maxd = trie->depth; |
| 257 | |
| 258 | return NULL; |
| 259 | } |
| 260 | |
| 261 | /* Enqueue the trie nodes referenced from the given tree in the |
| 262 | given queue. */ |
| 263 | static void |
| 264 | DEFUN(enqueue, (tree, last), struct tree *tree AND struct trie **last) |
| 265 | { |
| 266 | if (!tree) |
| 267 | return; |
| 268 | enqueue(tree->llink, last); |
| 269 | enqueue(tree->rlink, last); |
| 270 | (*last) = (*last)->next = tree->trie; |
| 271 | } |
| 272 | |
| 273 | /* Compute the Aho-Corasick failure function for the trie nodes referenced |
| 274 | from the given tree, given the failure function for their parent as |
| 275 | well as a last resort failure node. */ |
| 276 | static void |
| 277 | DEFUN(treefails, (tree, fail, recourse), |
| 278 | register struct tree *tree |
| 279 | AND struct trie *fail AND struct trie *recourse) |
| 280 | { |
| 281 | register struct tree *link; |
| 282 | |
| 283 | if (!tree) |
| 284 | return; |
| 285 | |
| 286 | treefails(tree->llink, fail, recourse); |
| 287 | treefails(tree->rlink, fail, recourse); |
| 288 | |
| 289 | /* Find, in the chain of fails going back to the root, the first |
| 290 | node that has a descendent on the current label. */ |
| 291 | while (fail) |
| 292 | { |
| 293 | link = fail->links; |
| 294 | while (link && tree->label != link->label) |
| 295 | if (tree->label < link->label) |
| 296 | link = link->llink; |
| 297 | else |
| 298 | link = link->rlink; |
| 299 | if (link) |
| 300 | { |
| 301 | tree->trie->fail = link->trie; |
| 302 | return; |
| 303 | } |
| 304 | fail = fail->fail; |
| 305 | } |
| 306 | |
| 307 | tree->trie->fail = recourse; |
| 308 | } |
| 309 | |
| 310 | /* Set delta entries for the links of the given tree such that |
| 311 | the preexisting delta value is larger than the current depth. */ |
| 312 | static void |
| 313 | DEFUN(treedelta, (tree, depth, delta), |
| 314 | register struct tree *tree AND register int depth AND int delta[]) |
| 315 | { |
| 316 | if (!tree) |
| 317 | return; |
| 318 | treedelta(tree->llink, depth, delta); |
| 319 | treedelta(tree->rlink, depth, delta); |
| 320 | if (depth < delta[tree->label]) |
| 321 | delta[tree->label] = depth; |
| 322 | } |
| 323 | |
| 324 | /* Return true if A has every label in B. */ |
| 325 | static int |
| 326 | DEFUN(hasevery, (a, b), register struct tree *a AND register struct tree *b) |
| 327 | { |
| 328 | if (!b) |
| 329 | return 1; |
| 330 | if (!hasevery(a, b->llink)) |
| 331 | return 0; |
| 332 | if (!hasevery(a, b->rlink)) |
| 333 | return 0; |
| 334 | while (a && b->label != a->label) |
| 335 | if (b->label < a->label) |
| 336 | a = a->llink; |
| 337 | else |
| 338 | a = a->rlink; |
| 339 | return !!a; |
| 340 | } |
| 341 | |
| 342 | /* Compute a vector, indexed by character code, of the trie nodes |
| 343 | referenced from the given tree. */ |
| 344 | static void |
| 345 | DEFUN(treenext, (tree, next), struct tree *tree AND struct trie *next[]) |
| 346 | { |
| 347 | if (!tree) |
| 348 | return; |
| 349 | treenext(tree->llink, next); |
| 350 | treenext(tree->rlink, next); |
| 351 | next[tree->label] = tree->trie; |
| 352 | } |
| 353 | |
| 354 | /* Compute the shift for each trie node, as well as the delta |
| 355 | table and next cache for the given keyword set. */ |
| 356 | const char * |
| 357 | DEFUN(kwsprep, (kws), kwset_t kws) |
| 358 | { |
| 359 | register struct kwset *kwset; |
| 360 | register int i; |
| 361 | register struct trie *curr, *fail; |
| 362 | register const char *trans; |
| 363 | int delta[NCHAR]; |
| 364 | struct trie *last, *next[NCHAR]; |
| 365 | |
| 366 | kwset = (struct kwset *) kws; |
| 367 | |
| 368 | /* Initial values for the delta table; will be changed later. The |
| 369 | delta entry for a given character is the smallest depth of any |
| 370 | node at which an outgoing edge is labeled by that character. */ |
| 371 | for (i = 0; i < NCHAR; ++i) |
| 372 | delta[i] = kwset->mind; |
| 373 | |
| 374 | /* Traverse the nodes of the trie in level order, simultaneously |
| 375 | computing the delta table, failure function, and shift function. */ |
| 376 | for (curr = last = kwset->trie; curr; curr = curr->next) |
| 377 | { |
| 378 | /* Enqueue the immediate descendents in the level order queue. */ |
| 379 | enqueue(curr->links, &last); |
| 380 | |
| 381 | curr->shift = kwset->mind; |
| 382 | curr->maxshift = kwset->mind; |
| 383 | |
| 384 | /* Update the delta table for the descendents of this node. */ |
| 385 | treedelta(curr->links, curr->depth, delta); |
| 386 | |
| 387 | /* Compute the failure function for the decendents of this node. */ |
| 388 | treefails(curr->links, curr->fail, kwset->trie); |
| 389 | |
| 390 | /* Update the shifts at each node in the current node's chain |
| 391 | of fails back to the root. */ |
| 392 | for (fail = curr->fail; fail; fail = fail->fail) |
| 393 | { |
| 394 | /* If the current node has some outgoing edge that the fail |
| 395 | doesn't, then the shift at the fail should be no larger |
| 396 | than the difference of their depths. */ |
| 397 | if (!hasevery(fail->links, curr->links)) |
| 398 | if (curr->depth - fail->depth < fail->shift) |
| 399 | fail->shift = curr->depth - fail->depth; |
| 400 | |
| 401 | /* If the current node is accepting then the shift at the |
| 402 | fail and its descendents should be no larger than the |
| 403 | difference of their depths. */ |
| 404 | if (curr->accepting && fail->maxshift > curr->depth - fail->depth) |
| 405 | fail->maxshift = curr->depth - fail->depth; |
| 406 | } |
| 407 | } |
| 408 | |
| 409 | /* Traverse the trie in level order again, fixing up all nodes whose |
| 410 | shift exceeds their inherited maxshift. */ |
| 411 | for (curr = kwset->trie->next; curr; curr = curr->next) |
| 412 | { |
| 413 | if (curr->maxshift > curr->parent->maxshift) |
| 414 | curr->maxshift = curr->parent->maxshift; |
| 415 | if (curr->shift > curr->maxshift) |
| 416 | curr->shift = curr->maxshift; |
| 417 | } |
| 418 | |
| 419 | /* Create a vector, indexed by character code, of the outgoing links |
| 420 | from the root node. */ |
| 421 | for (i = 0; i < NCHAR; ++i) |
| 422 | next[i] = NULL; |
| 423 | treenext(kwset->trie->links, next); |
| 424 | |
| 425 | /* Fix things up for any translation table. */ |
| 426 | if (trans = kwset->trans) |
| 427 | for (i = 0; i < NCHAR; ++i) |
| 428 | { |
| 429 | kwset->delta[i] = delta[(unsigned char) trans[i]]; |
| 430 | kwset->next[i] = next[(unsigned char) trans[i]]; |
| 431 | } |
| 432 | else |
| 433 | for (i = 0; i < NCHAR; ++i) |
| 434 | { |
| 435 | kwset->delta[i] = delta[i]; |
| 436 | kwset->next[i] = next[i]; |
| 437 | } |
| 438 | |
| 439 | return NULL; |
| 440 | } |
| 441 | |
| 442 | /* Search through the given text for a match of any member of the |
| 443 | given keyword set. Return a pointer to the first character of |
| 444 | the matching substring, or NULL if no match is found. If FOUNDLEN |
| 445 | is non-NULL store in the referenced location the length of the |
| 446 | matching substring. Similarly, if FOUNDIDX is non-NULL, store |
| 447 | in the referenced location the index number of the particular |
| 448 | keyword matched. */ |
| 449 | char * |
| 450 | DEFUN(kwsexec, (kws, text, len, kwsmatch), |
| 451 | kwset_t kws AND char *text AND size_t len AND struct kwsmatch *kwsmatch) |
| 452 | { |
| 453 | struct kwset *kwset; |
| 454 | struct trie **next, *trie, *accept; |
| 455 | char *beg, *lim, *mch, *lmch; |
| 456 | register unsigned char c; |
| 457 | register int *delta, d; |
| 458 | register char *end, *qlim; |
| 459 | register struct tree *tree; |
| 460 | register const char *trans; |
| 461 | |
| 462 | /* Initialize register copies and look for easy ways out. */ |
| 463 | kwset = (struct kwset *) kws; |
| 464 | if (len < kwset->mind) |
| 465 | return NULL; |
| 466 | next = kwset->next; |
| 467 | delta = kwset->delta; |
| 468 | trans = kwset->trans; |
| 469 | lim = text + len; |
| 470 | end = text; |
| 471 | if (d = kwset->mind) |
| 472 | mch = NULL; |
| 473 | else |
| 474 | { |
| 475 | mch = text, accept = kwset->trie; |
| 476 | goto match; |
| 477 | } |
| 478 | |
| 479 | if (len >= 4 * kwset->mind) |
| 480 | qlim = lim - 4 * kwset->mind; |
| 481 | else |
| 482 | qlim = NULL; |
| 483 | |
| 484 | while (lim - end >= d) |
| 485 | { |
| 486 | if (qlim && end <= qlim) |
| 487 | { |
| 488 | end += d - 1; |
| 489 | while ((d = delta[c = *end]) && end < qlim) |
| 490 | { |
| 491 | end += d; |
| 492 | end += delta[(unsigned char) *end]; |
| 493 | end += delta[(unsigned char) *end]; |
| 494 | } |
| 495 | ++end; |
| 496 | } |
| 497 | else |
| 498 | d = delta[c = (end += d)[-1]]; |
| 499 | if (d) |
| 500 | continue; |
| 501 | beg = end - 1; |
| 502 | trie = next[c]; |
| 503 | if (trie->accepting) |
| 504 | { |
| 505 | mch = beg; |
| 506 | accept = trie; |
| 507 | } |
| 508 | d = trie->shift; |
| 509 | while (beg > text) |
| 510 | { |
| 511 | c = trans ? trans[(unsigned char) *--beg] : *--beg; |
| 512 | tree = trie->links; |
| 513 | while (tree && c != tree->label) |
| 514 | if (c < tree->label) |
| 515 | tree = tree->llink; |
| 516 | else |
| 517 | tree = tree->rlink; |
| 518 | if (tree) |
| 519 | { |
| 520 | trie = tree->trie; |
| 521 | if (trie->accepting) |
| 522 | { |
| 523 | mch = beg; |
| 524 | accept = trie; |
| 525 | } |
| 526 | } |
| 527 | else |
| 528 | break; |
| 529 | d = trie->shift; |
| 530 | } |
| 531 | if (mch) |
| 532 | goto match; |
| 533 | } |
| 534 | return NULL; |
| 535 | |
| 536 | match: |
| 537 | /* Given a known match, find the longest possible match anchored |
| 538 | at or before its starting point. This is nearly a verbatim |
| 539 | copy of the preceding main search loops. */ |
| 540 | if (lim - mch > kwset->maxd) |
| 541 | lim = mch + kwset->maxd; |
| 542 | lmch = NULL; |
| 543 | d = 1; |
| 544 | while (lim - end >= d) |
| 545 | { |
| 546 | if (d = delta[c = (end += d)[-1]]) |
| 547 | continue; |
| 548 | beg = end - 1; |
| 549 | if (!(trie = next[c])) |
| 550 | { |
| 551 | d = 1; |
| 552 | continue; |
| 553 | } |
| 554 | if (trie->accepting && beg <= mch) |
| 555 | { |
| 556 | lmch = beg; |
| 557 | accept = trie; |
| 558 | } |
| 559 | d = trie->shift; |
| 560 | while (beg > text) |
| 561 | { |
| 562 | c = trans ? trans[(unsigned char) *--beg] : *--beg; |
| 563 | tree = trie->links; |
| 564 | while (tree && c != tree->label) |
| 565 | if (c < tree->label) |
| 566 | tree = tree->llink; |
| 567 | else |
| 568 | tree = tree->rlink; |
| 569 | if (tree) |
| 570 | { |
| 571 | trie = tree->trie; |
| 572 | if (trie->accepting && beg <= mch) |
| 573 | { |
| 574 | lmch = beg; |
| 575 | accept = trie; |
| 576 | } |
| 577 | } |
| 578 | else |
| 579 | break; |
| 580 | d = trie->shift; |
| 581 | } |
| 582 | if (lmch) |
| 583 | { |
| 584 | mch = lmch; |
| 585 | goto match; |
| 586 | } |
| 587 | if (!d) |
| 588 | d = 1; |
| 589 | } |
| 590 | |
| 591 | if (kwsmatch) |
| 592 | { |
| 593 | kwsmatch->index = accept->accepting / 2; |
| 594 | kwsmatch->beg[0] = mch; |
| 595 | kwsmatch->size[0] = accept->depth; |
| 596 | } |
| 597 | return mch; |
| 598 | } |
| 599 | |
| 600 | /* Free the components of the given keyword set. */ |
| 601 | void |
| 602 | DEFUN(kwsfree, (kws), kwset_t kws) |
| 603 | { |
| 604 | struct kwset *kwset; |
| 605 | |
| 606 | kwset = (struct kwset *) kws; |
| 607 | obstack_free(&kwset->obstack, (PTR) NULL); |
| 608 | free((PTR) kws); |
| 609 | } |