1 /**************************************************************** 2 Copyright (C) Lucent Technologies 1997 3 All Rights Reserved 4 5 Permission to use, copy, modify, and distribute this software and 6 its documentation for any purpose and without fee is hereby 7 granted, provided that the above copyright notice appear in all 8 copies and that both that the copyright notice and this 9 permission notice and warranty disclaimer appear in supporting 10 documentation, and that the name Lucent Technologies or any of 11 its entities not be used in advertising or publicity pertaining 12 to distribution of the software without specific, written prior 13 permission. 14 15 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 16 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 17 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 18 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 20 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 21 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 22 THIS SOFTWARE. 23 ****************************************************************/ 24 25 /* lasciate ogne speranza, voi ch'entrate. */ 26 27 #define DEBUG 28 29 #include <ctype.h> 30 #include <stdio.h> 31 #include <string.h> 32 #include <stdlib.h> 33 #include "awk.h" 34 #include "ytab.h" 35 36 #define HAT (NCHARS-2) /* matches ^ in regular expr */ 37 /* NCHARS is 2**n */ 38 #define MAXLIN 22 39 40 #define type(v) (v)->nobj /* badly overloaded here */ 41 #define info(v) (v)->ntype /* badly overloaded here */ 42 #define left(v) (v)->narg[0] 43 #define right(v) (v)->narg[1] 44 #define parent(v) (v)->nnext 45 46 #define LEAF case CCL: case NCCL: case CHAR: case DOT: case FINAL: case ALL: 47 #define UNARY case STAR: case PLUS: case QUEST: 48 49 /* encoding in tree Nodes: 50 leaf (CCL, NCCL, CHAR, DOT, FINAL, ALL): 51 left is index, right contains value or pointer to value 52 unary (STAR, PLUS, QUEST): left is child, right is null 53 binary (CAT, OR): left and right are children 54 parent contains pointer to parent 55 */ 56 57 58 int *setvec; 59 int *tmpset; 60 int maxsetvec = 0; 61 62 int rtok; /* next token in current re */ 63 int rlxval; 64 static uschar *rlxstr; 65 static uschar *prestr; /* current position in current re */ 66 static uschar *lastre; /* origin of last re */ 67 68 static int setcnt; 69 static int poscnt; 70 71 char *patbeg; 72 int patlen; 73 74 #define NFA 20 /* cache this many dynamic fa's */ 75 fa *fatab[NFA]; 76 int nfatab = 0; /* entries in fatab */ 77 78 fa *makedfa(char *s, int anchor) /* returns dfa for reg expr s */ 79 { 80 int i, use, nuse; 81 fa *pfa; 82 static int now = 1; 83 84 if (setvec == 0) { /* first time through any RE */ 85 maxsetvec = MAXLIN; 86 setvec = (int *) malloc(maxsetvec * sizeof(int)); 87 tmpset = (int *) malloc(maxsetvec * sizeof(int)); 88 if (setvec == 0 || tmpset == 0) 89 overflo("out of space initializing makedfa"); 90 } 91 92 if (compile_time) /* a constant for sure */ 93 return mkdfa(s, anchor); 94 for (i = 0; i < nfatab; i++) /* is it there already? */ 95 if (fatab[i]->anchor == anchor 96 && strcmp(fatab[i]->restr, s) == 0) { 97 fatab[i]->use = now++; 98 return fatab[i]; 99 } 100 pfa = mkdfa(s, anchor); 101 if (nfatab < NFA) { /* room for another */ 102 fatab[nfatab] = pfa; 103 fatab[nfatab]->use = now++; 104 nfatab++; 105 return pfa; 106 } 107 use = fatab[0]->use; /* replace least-recently used */ 108 nuse = 0; 109 for (i = 1; i < nfatab; i++) 110 if (fatab[i]->use < use) { 111 use = fatab[i]->use; 112 nuse = i; 113 } 114 freefa(fatab[nuse]); 115 fatab[nuse] = pfa; 116 pfa->use = now++; 117 return pfa; 118 } 119 120 fa *mkdfa(char *s, int anchor) /* does the real work of making a dfa */ 121 /* anchor = 1 for anchored matches, else 0 */ 122 { 123 Node *p, *p1; 124 fa *f; 125 126 p = reparse(s); 127 p1 = op2(CAT, op2(STAR, op2(ALL, NIL, NIL), NIL), p); 128 /* put ALL STAR in front of reg. exp. */ 129 p1 = op2(CAT, p1, op2(FINAL, NIL, NIL)); 130 /* put FINAL after reg. exp. */ 131 132 poscnt = 0; 133 penter(p1); /* enter parent pointers and leaf indices */ 134 if ((f = (fa *) calloc(1, sizeof(fa) + poscnt*sizeof(rrow))) == NULL) 135 overflo("out of space for fa"); 136 f->accept = poscnt-1; /* penter has computed number of positions in re */ 137 cfoll(f, p1); /* set up follow sets */ 138 freetr(p1); 139 if ((f->posns[0] = (int *) calloc(1, *(f->re[0].lfollow)*sizeof(int))) == NULL) 140 overflo("out of space in makedfa"); 141 if ((f->posns[1] = (int *) calloc(1, sizeof(int))) == NULL) 142 overflo("out of space in makedfa"); 143 *f->posns[1] = 0; 144 f->initstat = makeinit(f, anchor); 145 f->anchor = anchor; 146 f->restr = (uschar *) tostring(s); 147 return f; 148 } 149 150 int makeinit(fa *f, int anchor) 151 { 152 int i, k; 153 154 f->curstat = 2; 155 f->out[2] = 0; 156 f->reset = 0; 157 k = *(f->re[0].lfollow); 158 xfree(f->posns[2]); 159 if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL) 160 overflo("out of space in makeinit"); 161 for (i=0; i <= k; i++) { 162 (f->posns[2])[i] = (f->re[0].lfollow)[i]; 163 } 164 if ((f->posns[2])[1] == f->accept) 165 f->out[2] = 1; 166 for (i=0; i < NCHARS; i++) 167 f->gototab[2][i] = 0; 168 f->curstat = cgoto(f, 2, HAT); 169 if (anchor) { 170 *f->posns[2] = k-1; /* leave out position 0 */ 171 for (i=0; i < k; i++) { 172 (f->posns[0])[i] = (f->posns[2])[i]; 173 } 174 175 f->out[0] = f->out[2]; 176 if (f->curstat != 2) 177 --(*f->posns[f->curstat]); 178 } 179 return f->curstat; 180 } 181 182 void penter(Node *p) /* set up parent pointers and leaf indices */ 183 { 184 switch (type(p)) { 185 LEAF 186 info(p) = poscnt; 187 poscnt++; 188 break; 189 UNARY 190 penter(left(p)); 191 parent(left(p)) = p; 192 break; 193 case CAT: 194 case OR: 195 penter(left(p)); 196 penter(right(p)); 197 parent(left(p)) = p; 198 parent(right(p)) = p; 199 break; 200 default: /* can't happen */ 201 FATAL("can't happen: unknown type %d in penter", type(p)); 202 break; 203 } 204 } 205 206 void freetr(Node *p) /* free parse tree */ 207 { 208 switch (type(p)) { 209 LEAF 210 xfree(p); 211 break; 212 UNARY 213 freetr(left(p)); 214 xfree(p); 215 break; 216 case CAT: 217 case OR: 218 freetr(left(p)); 219 freetr(right(p)); 220 xfree(p); 221 break; 222 default: /* can't happen */ 223 FATAL("can't happen: unknown type %d in freetr", type(p)); 224 break; 225 } 226 } 227 228 /* in the parsing of regular expressions, metacharacters like . have */ 229 /* to be seen literally; \056 is not a metacharacter. */ 230 231 int hexstr(char **pp) /* find and eval hex string at pp, return new p */ 232 { /* only pick up one 8-bit byte (2 chars) */ 233 uschar *p; 234 int n = 0; 235 int i; 236 237 for (i = 0, p = (uschar *) *pp; i < 2 && isxdigit(*p); i++, p++) { 238 if (isdigit(*p)) 239 n = 16 * n + *p - '0'; 240 else if (*p >= 'a' && *p <= 'f') 241 n = 16 * n + *p - 'a' + 10; 242 else if (*p >= 'A' && *p <= 'F') 243 n = 16 * n + *p - 'A' + 10; 244 } 245 *pp = (char *) p; 246 return n; 247 } 248 249 #define isoctdigit(c) ((c) >= '0' && (c) <= '7') /* multiple use of arg */ 250 251 int quoted(char **pp) /* pick up next thing after a \\ */ 252 /* and increment *pp */ 253 { 254 char *p = *pp; 255 int c; 256 257 if ((c = *p++) == 't') 258 c = '\t'; 259 else if (c == 'n') 260 c = '\n'; 261 else if (c == 'f') 262 c = '\f'; 263 else if (c == 'r') 264 c = '\r'; 265 else if (c == 'b') 266 c = '\b'; 267 else if (c == '\\') 268 c = '\\'; 269 else if (c == 'x') { /* hexadecimal goo follows */ 270 c = hexstr(&p); /* this adds a null if number is invalid */ 271 } else if (isoctdigit(c)) { /* \d \dd \ddd */ 272 int n = c - '0'; 273 if (isoctdigit(*p)) { 274 n = 8 * n + *p++ - '0'; 275 if (isoctdigit(*p)) 276 n = 8 * n + *p++ - '0'; 277 } 278 c = n; 279 } /* else */ 280 /* c = c; */ 281 *pp = p; 282 return c; 283 } 284 285 char *cclenter(char *argp) /* add a character class */ 286 { 287 int i, c, c2; 288 uschar *p = (uschar *) argp; 289 uschar *op, *bp; 290 static uschar *buf = 0; 291 static int bufsz = 100; 292 293 op = p; 294 if (buf == 0 && (buf = (uschar *) malloc(bufsz)) == NULL) 295 FATAL("out of space for character class [%.10s...] 1", p); 296 bp = buf; 297 for (i = 0; (c = *p++) != 0; ) { 298 if (c == '\\') { 299 c = quoted((char **) &p); 300 } else if (c == '-' && i > 0 && bp[-1] != 0) { 301 if (*p != 0) { 302 c = bp[-1]; 303 c2 = *p++; 304 if (c2 == '\\') 305 c2 = quoted((char **) &p); 306 if (c > c2) { /* empty; ignore */ 307 bp--; 308 i--; 309 continue; 310 } 311 while (c < c2) { 312 if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, 0)) 313 FATAL("out of space for character class [%.10s...] 2", p); 314 *bp++ = ++c; 315 i++; 316 } 317 continue; 318 } 319 } 320 if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, 0)) 321 FATAL("out of space for character class [%.10s...] 3", p); 322 *bp++ = c; 323 i++; 324 } 325 *bp = 0; 326 dprintf( ("cclenter: in = |%s|, out = |%s|\n", op, buf) ); 327 xfree(op); 328 return (char *) tostring((char *) buf); 329 } 330 331 void overflo(char *s) 332 { 333 FATAL("regular expression too big: %.30s...", s); 334 } 335 336 void cfoll(fa *f, Node *v) /* enter follow set of each leaf of vertex v into lfollow[leaf] */ 337 { 338 int i; 339 int *p; 340 341 switch (type(v)) { 342 LEAF 343 f->re[info(v)].ltype = type(v); 344 f->re[info(v)].lval.np = right(v); 345 while (f->accept >= maxsetvec) { /* guessing here! */ 346 maxsetvec *= 4; 347 setvec = (int *) realloc(setvec, maxsetvec * sizeof(int)); 348 tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int)); 349 if (setvec == 0 || tmpset == 0) 350 overflo("out of space in cfoll()"); 351 } 352 for (i = 0; i <= f->accept; i++) 353 setvec[i] = 0; 354 setcnt = 0; 355 follow(v); /* computes setvec and setcnt */ 356 if ((p = (int *) calloc(1, (setcnt+1)*sizeof(int))) == NULL) 357 overflo("out of space building follow set"); 358 f->re[info(v)].lfollow = p; 359 *p = setcnt; 360 for (i = f->accept; i >= 0; i--) 361 if (setvec[i] == 1) 362 *++p = i; 363 break; 364 UNARY 365 cfoll(f,left(v)); 366 break; 367 case CAT: 368 case OR: 369 cfoll(f,left(v)); 370 cfoll(f,right(v)); 371 break; 372 default: /* can't happen */ 373 FATAL("can't happen: unknown type %d in cfoll", type(v)); 374 } 375 } 376 377 int first(Node *p) /* collects initially active leaves of p into setvec */ 378 /* returns 1 if p matches empty string */ 379 { 380 int b, lp; 381 382 switch (type(p)) { 383 LEAF 384 lp = info(p); /* look for high-water mark of subscripts */ 385 while (setcnt >= maxsetvec || lp >= maxsetvec) { /* guessing here! */ 386 maxsetvec *= 4; 387 setvec = (int *) realloc(setvec, maxsetvec * sizeof(int)); 388 tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int)); 389 if (setvec == 0 || tmpset == 0) 390 overflo("out of space in first()"); 391 } 392 if (setvec[lp] != 1) { 393 setvec[lp] = 1; 394 setcnt++; 395 } 396 if (type(p) == CCL && (*(char *) right(p)) == '\0') 397 return(0); /* empty CCL */ 398 else return(1); 399 case PLUS: 400 if (first(left(p)) == 0) return(0); 401 return(1); 402 case STAR: 403 case QUEST: 404 first(left(p)); 405 return(0); 406 case CAT: 407 if (first(left(p)) == 0 && first(right(p)) == 0) return(0); 408 return(1); 409 case OR: 410 b = first(right(p)); 411 if (first(left(p)) == 0 || b == 0) return(0); 412 return(1); 413 } 414 FATAL("can't happen: unknown type %d in first", type(p)); /* can't happen */ 415 return(-1); 416 } 417 418 void follow(Node *v) /* collects leaves that can follow v into setvec */ 419 { 420 Node *p; 421 422 if (type(v) == FINAL) 423 return; 424 p = parent(v); 425 switch (type(p)) { 426 case STAR: 427 case PLUS: 428 first(v); 429 follow(p); 430 return; 431 432 case OR: 433 case QUEST: 434 follow(p); 435 return; 436 437 case CAT: 438 if (v == left(p)) { /* v is left child of p */ 439 if (first(right(p)) == 0) { 440 follow(p); 441 return; 442 } 443 } else /* v is right child */ 444 follow(p); 445 return; 446 } 447 } 448 449 int member(int c, char *sarg) /* is c in s? */ 450 { 451 uschar *s = (uschar *) sarg; 452 453 while (*s) 454 if (c == *s++) 455 return(1); 456 return(0); 457 } 458 459 int match(fa *f, char *p0) /* shortest match ? */ 460 { 461 int s, ns; 462 uschar *p = (uschar *) p0; 463 464 s = f->reset ? makeinit(f,0) : f->initstat; 465 if (f->out[s]) 466 return(1); 467 do { 468 if ((ns = f->gototab[s][*p]) != 0) 469 s = ns; 470 else 471 s = cgoto(f, s, *p); 472 if (f->out[s]) 473 return(1); 474 } while (*p++ != 0); 475 return(0); 476 } 477 478 int pmatch(fa *f, char *p0) /* longest match, for sub */ 479 { 480 int s, ns; 481 uschar *p = (uschar *) p0; 482 uschar *q; 483 int i, k; 484 485 s = f->reset ? makeinit(f,1) : f->initstat; 486 patbeg = (char *) p; 487 patlen = -1; 488 do { 489 q = p; 490 do { 491 if (f->out[s]) /* final state */ 492 patlen = q-p; 493 if ((ns = f->gototab[s][*q]) != 0) 494 s = ns; 495 else 496 s = cgoto(f, s, *q); 497 if (s == 1) { /* no transition */ 498 if (patlen >= 0) { 499 patbeg = (char *) p; 500 return(1); 501 } 502 else 503 goto nextin; /* no match */ 504 } 505 } while (*q++ != 0); 506 if (f->out[s]) 507 patlen = q-p-1; /* don't count $ */ 508 if (patlen >= 0) { 509 patbeg = (char *) p; 510 return(1); 511 } 512 nextin: 513 s = 2; 514 if (f->reset) { 515 for (i = 2; i <= f->curstat; i++) 516 xfree(f->posns[i]); 517 k = *f->posns[0]; 518 if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL) 519 overflo("out of space in pmatch"); 520 for (i = 0; i <= k; i++) 521 (f->posns[2])[i] = (f->posns[0])[i]; 522 f->initstat = f->curstat = 2; 523 f->out[2] = f->out[0]; 524 for (i = 0; i < NCHARS; i++) 525 f->gototab[2][i] = 0; 526 } 527 } while (*p++ != 0); 528 return (0); 529 } 530 531 int nematch(fa *f, char *p0) /* non-empty match, for sub */ 532 { 533 int s, ns; 534 uschar *p = (uschar *) p0; 535 uschar *q; 536 int i, k; 537 538 s = f->reset ? makeinit(f,1) : f->initstat; 539 patlen = -1; 540 while (*p) { 541 q = p; 542 do { 543 if (f->out[s]) /* final state */ 544 patlen = q-p; 545 if ((ns = f->gototab[s][*q]) != 0) 546 s = ns; 547 else 548 s = cgoto(f, s, *q); 549 if (s == 1) { /* no transition */ 550 if (patlen > 0) { 551 patbeg = (char *) p; 552 return(1); 553 } else 554 goto nnextin; /* no nonempty match */ 555 } 556 } while (*q++ != 0); 557 if (f->out[s]) 558 patlen = q-p-1; /* don't count $ */ 559 if (patlen > 0 ) { 560 patbeg = (char *) p; 561 return(1); 562 } 563 nnextin: 564 s = 2; 565 if (f->reset) { 566 for (i = 2; i <= f->curstat; i++) 567 xfree(f->posns[i]); 568 k = *f->posns[0]; 569 if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL) 570 overflo("out of state space"); 571 for (i = 0; i <= k; i++) 572 (f->posns[2])[i] = (f->posns[0])[i]; 573 f->initstat = f->curstat = 2; 574 f->out[2] = f->out[0]; 575 for (i = 0; i < NCHARS; i++) 576 f->gototab[2][i] = 0; 577 } 578 p++; 579 } 580 return (0); 581 } 582 583 Node *reparse(char *p) /* parses regular expression pointed to by p */ 584 { /* uses relex() to scan regular expression */ 585 Node *np; 586 587 dprintf( ("reparse <%s>\n", p) ); 588 lastre = prestr = (uschar *) p; /* prestr points to string to be parsed */ 589 rtok = relex(); 590 if (rtok == '\0') 591 FATAL("empty regular expression"); 592 np = regexp(); 593 if (rtok != '\0') 594 FATAL("syntax error in regular expression %s at %s", lastre, prestr); 595 return(np); 596 } 597 598 Node *regexp(void) /* top-level parse of reg expr */ 599 { 600 return (alt(concat(primary()))); 601 } 602 603 Node *primary(void) 604 { 605 Node *np; 606 607 switch (rtok) { 608 case CHAR: 609 np = op2(CHAR, NIL, itonp(rlxval)); 610 rtok = relex(); 611 return (unary(np)); 612 case ALL: 613 rtok = relex(); 614 return (unary(op2(ALL, NIL, NIL))); 615 case DOT: 616 rtok = relex(); 617 return (unary(op2(DOT, NIL, NIL))); 618 case CCL: 619 np = op2(CCL, NIL, (Node*) cclenter((char *) rlxstr)); 620 rtok = relex(); 621 return (unary(np)); 622 case NCCL: 623 np = op2(NCCL, NIL, (Node *) cclenter((char *) rlxstr)); 624 rtok = relex(); 625 return (unary(np)); 626 case '^': 627 rtok = relex(); 628 return (unary(op2(CHAR, NIL, itonp(HAT)))); 629 case '$': 630 rtok = relex(); 631 return (unary(op2(CHAR, NIL, NIL))); 632 case '(': 633 rtok = relex(); 634 if (rtok == ')') { /* special pleading for () */ 635 rtok = relex(); 636 return unary(op2(CCL, NIL, (Node *) tostring(""))); 637 } 638 np = regexp(); 639 if (rtok == ')') { 640 rtok = relex(); 641 return (unary(np)); 642 } 643 else 644 FATAL("syntax error in regular expression %s at %s", lastre, prestr); 645 default: 646 FATAL("illegal primary in regular expression %s at %s", lastre, prestr); 647 } 648 return 0; /*NOTREACHED*/ 649 } 650 651 Node *concat(Node *np) 652 { 653 switch (rtok) { 654 case CHAR: case DOT: case ALL: case CCL: case NCCL: case '$': case '(': 655 return (concat(op2(CAT, np, primary()))); 656 } 657 return (np); 658 } 659 660 Node *alt(Node *np) 661 { 662 if (rtok == OR) { 663 rtok = relex(); 664 return (alt(op2(OR, np, concat(primary())))); 665 } 666 return (np); 667 } 668 669 Node *unary(Node *np) 670 { 671 switch (rtok) { 672 case STAR: 673 rtok = relex(); 674 return (unary(op2(STAR, np, NIL))); 675 case PLUS: 676 rtok = relex(); 677 return (unary(op2(PLUS, np, NIL))); 678 case QUEST: 679 rtok = relex(); 680 return (unary(op2(QUEST, np, NIL))); 681 default: 682 return (np); 683 } 684 } 685 686 int relex(void) /* lexical analyzer for reparse */ 687 { 688 int c, n; 689 int cflag; 690 static uschar *buf = 0; 691 static int bufsz = 100; 692 uschar *bp; 693 694 switch (c = *prestr++) { 695 case '|': return OR; 696 case '*': return STAR; 697 case '+': return PLUS; 698 case '?': return QUEST; 699 case '.': return DOT; 700 case '\0': prestr--; return '\0'; 701 case '^': 702 case '$': 703 case '(': 704 case ')': 705 return c; 706 case '\\': 707 rlxval = quoted((char **) &prestr); 708 return CHAR; 709 default: 710 rlxval = c; 711 return CHAR; 712 case '[': 713 if (buf == 0 && (buf = (uschar *) malloc(bufsz)) == NULL) 714 FATAL("out of space in reg expr %.10s..", lastre); 715 bp = buf; 716 if (*prestr == '^') { 717 cflag = 1; 718 prestr++; 719 } 720 else 721 cflag = 0; 722 n = 2 * strlen(prestr)+1; 723 if (!adjbuf((char **) &buf, &bufsz, n, n, (char **) &bp, 0)) 724 FATAL("out of space for reg expr %.10s...", lastre); 725 for (; ; ) { 726 if ((c = *prestr++) == '\\') { 727 *bp++ = '\\'; 728 if ((c = *prestr++) == '\0') 729 FATAL("nonterminated character class %.20s...", lastre); 730 *bp++ = c; 731 /* } else if (c == '\n') { */ 732 /* FATAL("newline in character class %.20s...", lastre); */ 733 } else if (c == '\0') { 734 FATAL("nonterminated character class %.20s", lastre); 735 } else if (bp == buf) { /* 1st char is special */ 736 *bp++ = c; 737 } else if (c == ']') { 738 *bp++ = 0; 739 rlxstr = (uschar *) tostring((char *) buf); 740 if (cflag == 0) 741 return CCL; 742 else 743 return NCCL; 744 } else 745 *bp++ = c; 746 } 747 } 748 } 749 750 int cgoto(fa *f, int s, int c) 751 { 752 int i, j, k; 753 int *p, *q; 754 755 if (c < 0 || c > 255) 756 FATAL("can't happen: neg char %d in cgoto", c); 757 while (f->accept >= maxsetvec) { /* guessing here! */ 758 maxsetvec *= 4; 759 setvec = (int *) realloc(setvec, maxsetvec * sizeof(int)); 760 tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int)); 761 if (setvec == 0 || tmpset == 0) 762 overflo("out of space in cgoto()"); 763 } 764 for (i = 0; i <= f->accept; i++) 765 setvec[i] = 0; 766 setcnt = 0; 767 /* compute positions of gototab[s,c] into setvec */ 768 p = f->posns[s]; 769 for (i = 1; i <= *p; i++) { 770 if ((k = f->re[p[i]].ltype) != FINAL) { 771 if ((k == CHAR && c == ptoi(f->re[p[i]].lval.np)) 772 || (k == DOT && c != 0 && c != HAT) 773 || (k == ALL && c != 0) 774 || (k == CCL && member(c, (char *) f->re[p[i]].lval.up)) 775 || (k == NCCL && !member(c, (char *) f->re[p[i]].lval.up) && c != 0 && c != HAT)) { 776 q = f->re[p[i]].lfollow; 777 for (j = 1; j <= *q; j++) { 778 if (q[j] >= maxsetvec) { 779 maxsetvec *= 4; 780 setvec = (int *) realloc(setvec, maxsetvec * sizeof(int)); 781 tmpset = (int *) realloc(setvec, maxsetvec * sizeof(int)); 782 if (setvec == 0 || tmpset == 0) 783 overflo("cgoto overflow"); 784 } 785 if (setvec[q[j]] == 0) { 786 setcnt++; 787 setvec[q[j]] = 1; 788 } 789 } 790 } 791 } 792 } 793 /* determine if setvec is a previous state */ 794 tmpset[0] = setcnt; 795 j = 1; 796 for (i = f->accept; i >= 0; i--) 797 if (setvec[i]) { 798 tmpset[j++] = i; 799 } 800 /* tmpset == previous state? */ 801 for (i = 1; i <= f->curstat; i++) { 802 p = f->posns[i]; 803 if ((k = tmpset[0]) != p[0]) 804 goto different; 805 for (j = 1; j <= k; j++) 806 if (tmpset[j] != p[j]) 807 goto different; 808 /* setvec is state i */ 809 f->gototab[s][c] = i; 810 return i; 811 different:; 812 } 813 814 /* add tmpset to current set of states */ 815 if (f->curstat >= NSTATES-1) { 816 f->curstat = 2; 817 f->reset = 1; 818 for (i = 2; i < NSTATES; i++) 819 xfree(f->posns[i]); 820 } else 821 ++(f->curstat); 822 for (i = 0; i < NCHARS; i++) 823 f->gototab[f->curstat][i] = 0; 824 xfree(f->posns[f->curstat]); 825 if ((p = (int *) calloc(1, (setcnt+1)*sizeof(int))) == NULL) 826 overflo("out of space in cgoto"); 827 828 f->posns[f->curstat] = p; 829 f->gototab[s][c] = f->curstat; 830 for (i = 0; i <= setcnt; i++) 831 p[i] = tmpset[i]; 832 if (setvec[f->accept]) 833 f->out[f->curstat] = 1; 834 else 835 f->out[f->curstat] = 0; 836 return f->curstat; 837 } 838 839 840 void freefa(fa *f) /* free a finite automaton */ 841 { 842 int i; 843 844 if (f == NULL) 845 return; 846 for (i = 0; i <= f->curstat; i++) 847 xfree(f->posns[i]); 848 for (i = 0; i <= f->accept; i++) { 849 xfree(f->re[i].lfollow); 850 if (f->re[i].ltype == CCL || f->re[i].ltype == NCCL) 851 xfree((f->re[i].lval.np)); 852 } 853 xfree(f->restr); 854 xfree(f); 855 } 856