1 /* $OpenBSD: regcomp.c,v 1.20 2010/11/21 00:02:30 tedu Exp $ */ 2 /*- 3 * Copyright (c) 1992, 1993, 1994 Henry Spencer. 4 * Copyright (c) 1992, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Henry Spencer. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)regcomp.c 8.5 (Berkeley) 3/20/94 35 */ 36 37 #include <sys/types.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <ctype.h> 41 #include <limits.h> 42 #include <stdlib.h> 43 #include <regex.h> 44 45 #include "utils.h" 46 #include "regex2.h" 47 48 #include "cclass.h" 49 #include "cname.h" 50 51 /* 52 * parse structure, passed up and down to avoid global variables and 53 * other clumsinesses 54 */ 55 struct parse { 56 char *next; /* next character in RE */ 57 char *end; /* end of string (-> NUL normally) */ 58 int error; /* has an error been seen? */ 59 sop *strip; /* malloced strip */ 60 sopno ssize; /* malloced strip size (allocated) */ 61 sopno slen; /* malloced strip length (used) */ 62 int ncsalloc; /* number of csets allocated */ 63 struct re_guts *g; 64 # define NPAREN 10 /* we need to remember () 1-9 for back refs */ 65 sopno pbegin[NPAREN]; /* -> ( ([0] unused) */ 66 sopno pend[NPAREN]; /* -> ) ([0] unused) */ 67 }; 68 69 static void p_ere(struct parse *, int); 70 static void p_ere_exp(struct parse *); 71 static void p_str(struct parse *); 72 static void p_bre(struct parse *, int, int); 73 static int p_simp_re(struct parse *, int); 74 static int p_count(struct parse *); 75 static void p_bracket(struct parse *); 76 static void p_b_term(struct parse *, cset *); 77 static void p_b_cclass(struct parse *, cset *); 78 static void p_b_eclass(struct parse *, cset *); 79 static char p_b_symbol(struct parse *); 80 static char p_b_coll_elem(struct parse *, int); 81 static char othercase(int); 82 static void bothcases(struct parse *, int); 83 static void ordinary(struct parse *, int); 84 static void nonnewline(struct parse *); 85 static void repeat(struct parse *, sopno, int, int); 86 static int seterr(struct parse *, int); 87 static cset *allocset(struct parse *); 88 static void freeset(struct parse *, cset *); 89 static int freezeset(struct parse *, cset *); 90 static int firstch(struct parse *, cset *); 91 static int nch(struct parse *, cset *); 92 static void mcadd(struct parse *, cset *, char *); 93 static void mcinvert(struct parse *, cset *); 94 static void mccase(struct parse *, cset *); 95 static int isinsets(struct re_guts *, int); 96 static int samesets(struct re_guts *, int, int); 97 static void categorize(struct parse *, struct re_guts *); 98 static sopno dupl(struct parse *, sopno, sopno); 99 static void doemit(struct parse *, sop, size_t); 100 static void doinsert(struct parse *, sop, size_t, sopno); 101 static void dofwd(struct parse *, sopno, sop); 102 static void enlarge(struct parse *, sopno); 103 static void stripsnug(struct parse *, struct re_guts *); 104 static void findmust(struct parse *, struct re_guts *); 105 static sopno pluscount(struct parse *, struct re_guts *); 106 107 static char nuls[10]; /* place to point scanner in event of error */ 108 109 /* 110 * macros for use with parse structure 111 * BEWARE: these know that the parse structure is named `p' !!! 112 */ 113 #define PEEK() (*p->next) 114 #define PEEK2() (*(p->next+1)) 115 #define MORE() (p->next < p->end) 116 #define MORE2() (p->next+1 < p->end) 117 #define SEE(c) (MORE() && PEEK() == (c)) 118 #define SEETWO(a, b) (MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b)) 119 #define EAT(c) ((SEE(c)) ? (NEXT(), 1) : 0) 120 #define EATTWO(a, b) ((SEETWO(a, b)) ? (NEXT2(), 1) : 0) 121 #define NEXT() (p->next++) 122 #define NEXT2() (p->next += 2) 123 #define NEXTn(n) (p->next += (n)) 124 #define GETNEXT() (*p->next++) 125 #define SETERROR(e) seterr(p, (e)) 126 #define REQUIRE(co, e) ((co) || SETERROR(e)) 127 #define MUSTSEE(c, e) (REQUIRE(MORE() && PEEK() == (c), e)) 128 #define MUSTEAT(c, e) (REQUIRE(MORE() && GETNEXT() == (c), e)) 129 #define MUSTNOTSEE(c, e) (REQUIRE(!MORE() || PEEK() != (c), e)) 130 #define EMIT(op, sopnd) doemit(p, (sop)(op), (size_t)(sopnd)) 131 #define INSERT(op, pos) doinsert(p, (sop)(op), HERE()-(pos)+1, pos) 132 #define AHEAD(pos) dofwd(p, pos, HERE()-(pos)) 133 #define ASTERN(sop, pos) EMIT(sop, HERE()-pos) 134 #define HERE() (p->slen) 135 #define THERE() (p->slen - 1) 136 #define THERETHERE() (p->slen - 2) 137 #define DROP(n) (p->slen -= (n)) 138 139 #ifndef NDEBUG 140 static int never = 0; /* for use in asserts; shuts lint up */ 141 #else 142 #define never 0 /* some <assert.h>s have bugs too */ 143 #endif 144 145 /* 146 - regcomp - interface for parser and compilation 147 */ 148 int /* 0 success, otherwise REG_something */ 149 regcomp(regex_t *preg, const char *pattern, int cflags) 150 { 151 struct parse pa; 152 struct re_guts *g; 153 struct parse *p = &pa; 154 int i; 155 size_t len; 156 #ifdef REDEBUG 157 # define GOODFLAGS(f) (f) 158 #else 159 # define GOODFLAGS(f) ((f)&~REG_DUMP) 160 #endif 161 162 cflags = GOODFLAGS(cflags); 163 if ((cflags®_EXTENDED) && (cflags®_NOSPEC)) 164 return(REG_INVARG); 165 166 if (cflags®_PEND) { 167 if (preg->re_endp < pattern) 168 return(REG_INVARG); 169 len = preg->re_endp - pattern; 170 } else 171 len = strlen((char *)pattern); 172 173 /* do the mallocs early so failure handling is easy */ 174 g = (struct re_guts *)malloc(sizeof(struct re_guts) + 175 (NC-1)*sizeof(cat_t)); 176 if (g == NULL) 177 return(REG_ESPACE); 178 p->ssize = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */ 179 p->strip = (sop *)calloc(p->ssize, sizeof(sop)); 180 p->slen = 0; 181 if (p->strip == NULL) { 182 free((char *)g); 183 return(REG_ESPACE); 184 } 185 186 /* set things up */ 187 p->g = g; 188 p->next = (char *)pattern; /* convenience; we do not modify it */ 189 p->end = p->next + len; 190 p->error = 0; 191 p->ncsalloc = 0; 192 for (i = 0; i < NPAREN; i++) { 193 p->pbegin[i] = 0; 194 p->pend[i] = 0; 195 } 196 g->csetsize = NC; 197 g->sets = NULL; 198 g->setbits = NULL; 199 g->ncsets = 0; 200 g->cflags = cflags; 201 g->iflags = 0; 202 g->nbol = 0; 203 g->neol = 0; 204 g->must = NULL; 205 g->mlen = 0; 206 g->nsub = 0; 207 g->ncategories = 1; /* category 0 is "everything else" */ 208 g->categories = &g->catspace[-(CHAR_MIN)]; 209 (void) memset((char *)g->catspace, 0, NC*sizeof(cat_t)); 210 g->backrefs = 0; 211 212 /* do it */ 213 EMIT(OEND, 0); 214 g->firststate = THERE(); 215 if (cflags®_EXTENDED) 216 p_ere(p, OUT); 217 else if (cflags®_NOSPEC) 218 p_str(p); 219 else 220 p_bre(p, OUT, OUT); 221 EMIT(OEND, 0); 222 g->laststate = THERE(); 223 224 /* tidy up loose ends and fill things in */ 225 categorize(p, g); 226 stripsnug(p, g); 227 findmust(p, g); 228 g->nplus = pluscount(p, g); 229 g->magic = MAGIC2; 230 preg->re_nsub = g->nsub; 231 preg->re_g = g; 232 preg->re_magic = MAGIC1; 233 #ifndef REDEBUG 234 /* not debugging, so can't rely on the assert() in regexec() */ 235 if (g->iflags&BAD) 236 SETERROR(REG_ASSERT); 237 #endif 238 239 /* win or lose, we're done */ 240 if (p->error != 0) /* lose */ 241 regfree(preg); 242 return(p->error); 243 } 244 245 /* 246 - p_ere - ERE parser top level, concatenation and alternation 247 */ 248 static void 249 p_ere(struct parse *p, int stop) /* character this ERE should end at */ 250 { 251 char c; 252 sopno prevback; 253 sopno prevfwd; 254 sopno conc; 255 int first = 1; /* is this the first alternative? */ 256 257 for (;;) { 258 /* do a bunch of concatenated expressions */ 259 conc = HERE(); 260 while (MORE() && (c = PEEK()) != '|' && c != stop) 261 p_ere_exp(p); 262 REQUIRE(HERE() != conc, REG_EMPTY); /* require nonempty */ 263 264 if (!EAT('|')) 265 break; /* NOTE BREAK OUT */ 266 267 if (first) { 268 INSERT(OCH_, conc); /* offset is wrong */ 269 prevfwd = conc; 270 prevback = conc; 271 first = 0; 272 } 273 ASTERN(OOR1, prevback); 274 prevback = THERE(); 275 AHEAD(prevfwd); /* fix previous offset */ 276 prevfwd = HERE(); 277 EMIT(OOR2, 0); /* offset is very wrong */ 278 } 279 280 if (!first) { /* tail-end fixups */ 281 AHEAD(prevfwd); 282 ASTERN(O_CH, prevback); 283 } 284 285 assert(!MORE() || SEE(stop)); 286 } 287 288 /* 289 - p_ere_exp - parse one subERE, an atom possibly followed by a repetition op 290 */ 291 static void 292 p_ere_exp(struct parse *p) 293 { 294 char c; 295 sopno pos; 296 int count; 297 int count2; 298 sopno subno; 299 int wascaret = 0; 300 301 assert(MORE()); /* caller should have ensured this */ 302 c = GETNEXT(); 303 304 pos = HERE(); 305 switch (c) { 306 case '(': 307 REQUIRE(MORE(), REG_EPAREN); 308 p->g->nsub++; 309 subno = p->g->nsub; 310 if (subno < NPAREN) 311 p->pbegin[subno] = HERE(); 312 EMIT(OLPAREN, subno); 313 if (!SEE(')')) 314 p_ere(p, ')'); 315 if (subno < NPAREN) { 316 p->pend[subno] = HERE(); 317 assert(p->pend[subno] != 0); 318 } 319 EMIT(ORPAREN, subno); 320 MUSTEAT(')', REG_EPAREN); 321 break; 322 case '^': 323 EMIT(OBOL, 0); 324 p->g->iflags |= USEBOL; 325 p->g->nbol++; 326 wascaret = 1; 327 break; 328 case '$': 329 EMIT(OEOL, 0); 330 p->g->iflags |= USEEOL; 331 p->g->neol++; 332 break; 333 case '|': 334 SETERROR(REG_EMPTY); 335 break; 336 case '*': 337 case '+': 338 case '?': 339 SETERROR(REG_BADRPT); 340 break; 341 case '.': 342 if (p->g->cflags®_NEWLINE) 343 nonnewline(p); 344 else 345 EMIT(OANY, 0); 346 break; 347 case '[': 348 p_bracket(p); 349 break; 350 case '\\': 351 REQUIRE(MORE(), REG_EESCAPE); 352 c = GETNEXT(); 353 ordinary(p, c); 354 break; 355 case '{': /* okay as ordinary except if digit follows */ 356 REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT); 357 /* FALLTHROUGH */ 358 default: 359 ordinary(p, c); 360 break; 361 } 362 363 if (!MORE()) 364 return; 365 c = PEEK(); 366 /* we call { a repetition if followed by a digit */ 367 if (!( c == '*' || c == '+' || c == '?' || 368 (c == '{' && MORE2() && isdigit((uch)PEEK2())) )) 369 return; /* no repetition, we're done */ 370 NEXT(); 371 372 REQUIRE(!wascaret, REG_BADRPT); 373 switch (c) { 374 case '*': /* implemented as +? */ 375 /* this case does not require the (y|) trick, noKLUDGE */ 376 INSERT(OPLUS_, pos); 377 ASTERN(O_PLUS, pos); 378 INSERT(OQUEST_, pos); 379 ASTERN(O_QUEST, pos); 380 break; 381 case '+': 382 INSERT(OPLUS_, pos); 383 ASTERN(O_PLUS, pos); 384 break; 385 case '?': 386 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */ 387 INSERT(OCH_, pos); /* offset slightly wrong */ 388 ASTERN(OOR1, pos); /* this one's right */ 389 AHEAD(pos); /* fix the OCH_ */ 390 EMIT(OOR2, 0); /* offset very wrong... */ 391 AHEAD(THERE()); /* ...so fix it */ 392 ASTERN(O_CH, THERETHERE()); 393 break; 394 case '{': 395 count = p_count(p); 396 if (EAT(',')) { 397 if (isdigit((uch)PEEK())) { 398 count2 = p_count(p); 399 REQUIRE(count <= count2, REG_BADBR); 400 } else /* single number with comma */ 401 count2 = INFINITY; 402 } else /* just a single number */ 403 count2 = count; 404 repeat(p, pos, count, count2); 405 if (!EAT('}')) { /* error heuristics */ 406 while (MORE() && PEEK() != '}') 407 NEXT(); 408 REQUIRE(MORE(), REG_EBRACE); 409 SETERROR(REG_BADBR); 410 } 411 break; 412 } 413 414 if (!MORE()) 415 return; 416 c = PEEK(); 417 if (!( c == '*' || c == '+' || c == '?' || 418 (c == '{' && MORE2() && isdigit((uch)PEEK2())) ) ) 419 return; 420 SETERROR(REG_BADRPT); 421 } 422 423 /* 424 - p_str - string (no metacharacters) "parser" 425 */ 426 static void 427 p_str(struct parse *p) 428 { 429 REQUIRE(MORE(), REG_EMPTY); 430 while (MORE()) 431 ordinary(p, GETNEXT()); 432 } 433 434 /* 435 - p_bre - BRE parser top level, anchoring and concatenation 436 * Giving end1 as OUT essentially eliminates the end1/end2 check. 437 * 438 * This implementation is a bit of a kludge, in that a trailing $ is first 439 * taken as an ordinary character and then revised to be an anchor. The 440 * only undesirable side effect is that '$' gets included as a character 441 * category in such cases. This is fairly harmless; not worth fixing. 442 * The amount of lookahead needed to avoid this kludge is excessive. 443 */ 444 static void 445 p_bre(struct parse *p, 446 int end1, /* first terminating character */ 447 int end2) /* second terminating character */ 448 { 449 sopno start = HERE(); 450 int first = 1; /* first subexpression? */ 451 int wasdollar = 0; 452 453 if (EAT('^')) { 454 EMIT(OBOL, 0); 455 p->g->iflags |= USEBOL; 456 p->g->nbol++; 457 } 458 while (MORE() && !SEETWO(end1, end2)) { 459 wasdollar = p_simp_re(p, first); 460 first = 0; 461 } 462 if (wasdollar) { /* oops, that was a trailing anchor */ 463 DROP(1); 464 EMIT(OEOL, 0); 465 p->g->iflags |= USEEOL; 466 p->g->neol++; 467 } 468 469 REQUIRE(HERE() != start, REG_EMPTY); /* require nonempty */ 470 } 471 472 /* 473 - p_simp_re - parse a simple RE, an atom possibly followed by a repetition 474 */ 475 static int /* was the simple RE an unbackslashed $? */ 476 p_simp_re(struct parse *p, 477 int starordinary) /* is a leading * an ordinary character? */ 478 { 479 int c; 480 int count; 481 int count2; 482 sopno pos; 483 int i; 484 sopno subno; 485 # define BACKSL (1<<CHAR_BIT) 486 487 pos = HERE(); /* repetion op, if any, covers from here */ 488 489 assert(MORE()); /* caller should have ensured this */ 490 c = GETNEXT(); 491 if (c == '\\') { 492 REQUIRE(MORE(), REG_EESCAPE); 493 c = BACKSL | GETNEXT(); 494 } 495 switch (c) { 496 case '.': 497 if (p->g->cflags®_NEWLINE) 498 nonnewline(p); 499 else 500 EMIT(OANY, 0); 501 break; 502 case '[': 503 p_bracket(p); 504 break; 505 case BACKSL|'{': 506 SETERROR(REG_BADRPT); 507 break; 508 case BACKSL|'(': 509 p->g->nsub++; 510 subno = p->g->nsub; 511 if (subno < NPAREN) 512 p->pbegin[subno] = HERE(); 513 EMIT(OLPAREN, subno); 514 /* the MORE here is an error heuristic */ 515 if (MORE() && !SEETWO('\\', ')')) 516 p_bre(p, '\\', ')'); 517 if (subno < NPAREN) { 518 p->pend[subno] = HERE(); 519 assert(p->pend[subno] != 0); 520 } 521 EMIT(ORPAREN, subno); 522 REQUIRE(EATTWO('\\', ')'), REG_EPAREN); 523 break; 524 case BACKSL|')': /* should not get here -- must be user */ 525 case BACKSL|'}': 526 SETERROR(REG_EPAREN); 527 break; 528 case BACKSL|'1': 529 case BACKSL|'2': 530 case BACKSL|'3': 531 case BACKSL|'4': 532 case BACKSL|'5': 533 case BACKSL|'6': 534 case BACKSL|'7': 535 case BACKSL|'8': 536 case BACKSL|'9': 537 i = (c&~BACKSL) - '0'; 538 assert(i < NPAREN); 539 if (p->pend[i] != 0) { 540 assert(i <= p->g->nsub); 541 EMIT(OBACK_, i); 542 assert(p->pbegin[i] != 0); 543 assert(OP(p->strip[p->pbegin[i]]) == OLPAREN); 544 assert(OP(p->strip[p->pend[i]]) == ORPAREN); 545 (void) dupl(p, p->pbegin[i]+1, p->pend[i]); 546 EMIT(O_BACK, i); 547 } else 548 SETERROR(REG_ESUBREG); 549 p->g->backrefs = 1; 550 break; 551 case '*': 552 REQUIRE(starordinary, REG_BADRPT); 553 /* FALLTHROUGH */ 554 default: 555 ordinary(p, (char)c); 556 break; 557 } 558 559 if (EAT('*')) { /* implemented as +? */ 560 /* this case does not require the (y|) trick, noKLUDGE */ 561 INSERT(OPLUS_, pos); 562 ASTERN(O_PLUS, pos); 563 INSERT(OQUEST_, pos); 564 ASTERN(O_QUEST, pos); 565 } else if (EATTWO('\\', '{')) { 566 count = p_count(p); 567 if (EAT(',')) { 568 if (MORE() && isdigit((uch)PEEK())) { 569 count2 = p_count(p); 570 REQUIRE(count <= count2, REG_BADBR); 571 } else /* single number with comma */ 572 count2 = INFINITY; 573 } else /* just a single number */ 574 count2 = count; 575 repeat(p, pos, count, count2); 576 if (!EATTWO('\\', '}')) { /* error heuristics */ 577 while (MORE() && !SEETWO('\\', '}')) 578 NEXT(); 579 REQUIRE(MORE(), REG_EBRACE); 580 SETERROR(REG_BADBR); 581 } 582 } else if (c == '$') /* $ (but not \$) ends it */ 583 return(1); 584 585 return(0); 586 } 587 588 /* 589 - p_count - parse a repetition count 590 */ 591 static int /* the value */ 592 p_count(struct parse *p) 593 { 594 int count = 0; 595 int ndigits = 0; 596 597 while (MORE() && isdigit((uch)PEEK()) && count <= DUPMAX) { 598 count = count*10 + (GETNEXT() - '0'); 599 ndigits++; 600 } 601 602 REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR); 603 return(count); 604 } 605 606 /* 607 - p_bracket - parse a bracketed character list 608 * 609 * Note a significant property of this code: if the allocset() did SETERROR, 610 * no set operations are done. 611 */ 612 static void 613 p_bracket(struct parse *p) 614 { 615 cset *cs; 616 int invert = 0; 617 618 /* Dept of Truly Sickening Special-Case Kludges */ 619 if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) { 620 EMIT(OBOW, 0); 621 NEXTn(6); 622 return; 623 } 624 if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) { 625 EMIT(OEOW, 0); 626 NEXTn(6); 627 return; 628 } 629 630 if ((cs = allocset(p)) == NULL) { 631 /* allocset did set error status in p */ 632 return; 633 } 634 635 if (EAT('^')) 636 invert++; /* make note to invert set at end */ 637 if (EAT(']')) 638 CHadd(cs, ']'); 639 else if (EAT('-')) 640 CHadd(cs, '-'); 641 while (MORE() && PEEK() != ']' && !SEETWO('-', ']')) 642 p_b_term(p, cs); 643 if (EAT('-')) 644 CHadd(cs, '-'); 645 MUSTEAT(']', REG_EBRACK); 646 647 if (p->error != 0) { /* don't mess things up further */ 648 freeset(p, cs); 649 return; 650 } 651 652 if (p->g->cflags®_ICASE) { 653 int i; 654 int ci; 655 656 for (i = p->g->csetsize - 1; i >= 0; i--) 657 if (CHIN(cs, i) && isalpha(i)) { 658 ci = othercase(i); 659 if (ci != i) 660 CHadd(cs, ci); 661 } 662 if (cs->multis != NULL) 663 mccase(p, cs); 664 } 665 if (invert) { 666 int i; 667 668 for (i = p->g->csetsize - 1; i >= 0; i--) 669 if (CHIN(cs, i)) 670 CHsub(cs, i); 671 else 672 CHadd(cs, i); 673 if (p->g->cflags®_NEWLINE) 674 CHsub(cs, '\n'); 675 if (cs->multis != NULL) 676 mcinvert(p, cs); 677 } 678 679 assert(cs->multis == NULL); /* xxx */ 680 681 if (nch(p, cs) == 1) { /* optimize singleton sets */ 682 ordinary(p, firstch(p, cs)); 683 freeset(p, cs); 684 } else 685 EMIT(OANYOF, freezeset(p, cs)); 686 } 687 688 /* 689 - p_b_term - parse one term of a bracketed character list 690 */ 691 static void 692 p_b_term(struct parse *p, cset *cs) 693 { 694 char c; 695 char start, finish; 696 int i; 697 698 /* classify what we've got */ 699 switch ((MORE()) ? PEEK() : '\0') { 700 case '[': 701 c = (MORE2()) ? PEEK2() : '\0'; 702 break; 703 case '-': 704 SETERROR(REG_ERANGE); 705 return; /* NOTE RETURN */ 706 break; 707 default: 708 c = '\0'; 709 break; 710 } 711 712 switch (c) { 713 case ':': /* character class */ 714 NEXT2(); 715 REQUIRE(MORE(), REG_EBRACK); 716 c = PEEK(); 717 REQUIRE(c != '-' && c != ']', REG_ECTYPE); 718 p_b_cclass(p, cs); 719 REQUIRE(MORE(), REG_EBRACK); 720 REQUIRE(EATTWO(':', ']'), REG_ECTYPE); 721 break; 722 case '=': /* equivalence class */ 723 NEXT2(); 724 REQUIRE(MORE(), REG_EBRACK); 725 c = PEEK(); 726 REQUIRE(c != '-' && c != ']', REG_ECOLLATE); 727 p_b_eclass(p, cs); 728 REQUIRE(MORE(), REG_EBRACK); 729 REQUIRE(EATTWO('=', ']'), REG_ECOLLATE); 730 break; 731 default: /* symbol, ordinary character, or range */ 732 /* xxx revision needed for multichar stuff */ 733 start = p_b_symbol(p); 734 if (SEE('-') && MORE2() && PEEK2() != ']') { 735 /* range */ 736 NEXT(); 737 if (EAT('-')) 738 finish = '-'; 739 else 740 finish = p_b_symbol(p); 741 } else 742 finish = start; 743 /* xxx what about signed chars here... */ 744 REQUIRE(start <= finish, REG_ERANGE); 745 for (i = start; i <= finish; i++) 746 CHadd(cs, i); 747 break; 748 } 749 } 750 751 /* 752 - p_b_cclass - parse a character-class name and deal with it 753 */ 754 static void 755 p_b_cclass(struct parse *p, cset *cs) 756 { 757 char *sp = p->next; 758 struct cclass *cp; 759 size_t len; 760 char *u; 761 char c; 762 763 while (MORE() && isalpha(PEEK())) 764 NEXT(); 765 len = p->next - sp; 766 for (cp = cclasses; cp->name != NULL; cp++) 767 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0') 768 break; 769 if (cp->name == NULL) { 770 /* oops, didn't find it */ 771 SETERROR(REG_ECTYPE); 772 return; 773 } 774 775 u = cp->chars; 776 while ((c = *u++) != '\0') 777 CHadd(cs, c); 778 for (u = cp->multis; *u != '\0'; u += strlen(u) + 1) 779 MCadd(p, cs, u); 780 } 781 782 /* 783 - p_b_eclass - parse an equivalence-class name and deal with it 784 * 785 * This implementation is incomplete. xxx 786 */ 787 static void 788 p_b_eclass(struct parse *p, cset *cs) 789 { 790 char c; 791 792 c = p_b_coll_elem(p, '='); 793 CHadd(cs, c); 794 } 795 796 /* 797 - p_b_symbol - parse a character or [..]ed multicharacter collating symbol 798 */ 799 static char /* value of symbol */ 800 p_b_symbol(struct parse *p) 801 { 802 char value; 803 804 REQUIRE(MORE(), REG_EBRACK); 805 if (!EATTWO('[', '.')) 806 return(GETNEXT()); 807 808 /* collating symbol */ 809 value = p_b_coll_elem(p, '.'); 810 REQUIRE(EATTWO('.', ']'), REG_ECOLLATE); 811 return(value); 812 } 813 814 /* 815 - p_b_coll_elem - parse a collating-element name and look it up 816 */ 817 static char /* value of collating element */ 818 p_b_coll_elem(struct parse *p, 819 int endc) /* name ended by endc,']' */ 820 { 821 char *sp = p->next; 822 struct cname *cp; 823 int len; 824 825 while (MORE() && !SEETWO(endc, ']')) 826 NEXT(); 827 if (!MORE()) { 828 SETERROR(REG_EBRACK); 829 return(0); 830 } 831 len = p->next - sp; 832 for (cp = cnames; cp->name != NULL; cp++) 833 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0') 834 return(cp->code); /* known name */ 835 if (len == 1) 836 return(*sp); /* single character */ 837 SETERROR(REG_ECOLLATE); /* neither */ 838 return(0); 839 } 840 841 /* 842 - othercase - return the case counterpart of an alphabetic 843 */ 844 static char /* if no counterpart, return ch */ 845 othercase(int ch) 846 { 847 ch = (uch)ch; 848 assert(isalpha(ch)); 849 if (isupper(ch)) 850 return ((uch)tolower(ch)); 851 else if (islower(ch)) 852 return ((uch)toupper(ch)); 853 else /* peculiar, but could happen */ 854 return(ch); 855 } 856 857 /* 858 - bothcases - emit a dualcase version of a two-case character 859 * 860 * Boy, is this implementation ever a kludge... 861 */ 862 static void 863 bothcases(struct parse *p, int ch) 864 { 865 char *oldnext = p->next; 866 char *oldend = p->end; 867 char bracket[3]; 868 869 ch = (uch)ch; 870 assert(othercase(ch) != ch); /* p_bracket() would recurse */ 871 p->next = bracket; 872 p->end = bracket+2; 873 bracket[0] = ch; 874 bracket[1] = ']'; 875 bracket[2] = '\0'; 876 p_bracket(p); 877 assert(p->next == bracket+2); 878 p->next = oldnext; 879 p->end = oldend; 880 } 881 882 /* 883 - ordinary - emit an ordinary character 884 */ 885 static void 886 ordinary(struct parse *p, int ch) 887 { 888 cat_t *cap = p->g->categories; 889 890 if ((p->g->cflags®_ICASE) && isalpha((uch)ch) && othercase(ch) != ch) 891 bothcases(p, ch); 892 else { 893 EMIT(OCHAR, (uch)ch); 894 if (cap[ch] == 0) 895 cap[ch] = p->g->ncategories++; 896 } 897 } 898 899 /* 900 - nonnewline - emit REG_NEWLINE version of OANY 901 * 902 * Boy, is this implementation ever a kludge... 903 */ 904 static void 905 nonnewline(struct parse *p) 906 { 907 char *oldnext = p->next; 908 char *oldend = p->end; 909 char bracket[4]; 910 911 p->next = bracket; 912 p->end = bracket+3; 913 bracket[0] = '^'; 914 bracket[1] = '\n'; 915 bracket[2] = ']'; 916 bracket[3] = '\0'; 917 p_bracket(p); 918 assert(p->next == bracket+3); 919 p->next = oldnext; 920 p->end = oldend; 921 } 922 923 /* 924 - repeat - generate code for a bounded repetition, recursively if needed 925 */ 926 static void 927 repeat(struct parse *p, 928 sopno start, /* operand from here to end of strip */ 929 int from, /* repeated from this number */ 930 int to) /* to this number of times (maybe INFINITY) */ 931 { 932 sopno finish = HERE(); 933 # define N 2 934 # define INF 3 935 # define REP(f, t) ((f)*8 + (t)) 936 # define MAP(n) (((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N) 937 sopno copy; 938 939 if (p->error != 0) /* head off possible runaway recursion */ 940 return; 941 942 assert(from <= to); 943 944 switch (REP(MAP(from), MAP(to))) { 945 case REP(0, 0): /* must be user doing this */ 946 DROP(finish-start); /* drop the operand */ 947 break; 948 case REP(0, 1): /* as x{1,1}? */ 949 case REP(0, N): /* as x{1,n}? */ 950 case REP(0, INF): /* as x{1,}? */ 951 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */ 952 INSERT(OCH_, start); /* offset is wrong... */ 953 repeat(p, start+1, 1, to); 954 ASTERN(OOR1, start); 955 AHEAD(start); /* ... fix it */ 956 EMIT(OOR2, 0); 957 AHEAD(THERE()); 958 ASTERN(O_CH, THERETHERE()); 959 break; 960 case REP(1, 1): /* trivial case */ 961 /* done */ 962 break; 963 case REP(1, N): /* as x?x{1,n-1} */ 964 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */ 965 INSERT(OCH_, start); 966 ASTERN(OOR1, start); 967 AHEAD(start); 968 EMIT(OOR2, 0); /* offset very wrong... */ 969 AHEAD(THERE()); /* ...so fix it */ 970 ASTERN(O_CH, THERETHERE()); 971 copy = dupl(p, start+1, finish+1); 972 assert(copy == finish+4); 973 repeat(p, copy, 1, to-1); 974 break; 975 case REP(1, INF): /* as x+ */ 976 INSERT(OPLUS_, start); 977 ASTERN(O_PLUS, start); 978 break; 979 case REP(N, N): /* as xx{m-1,n-1} */ 980 copy = dupl(p, start, finish); 981 repeat(p, copy, from-1, to-1); 982 break; 983 case REP(N, INF): /* as xx{n-1,INF} */ 984 copy = dupl(p, start, finish); 985 repeat(p, copy, from-1, to); 986 break; 987 default: /* "can't happen" */ 988 SETERROR(REG_ASSERT); /* just in case */ 989 break; 990 } 991 } 992 993 /* 994 - seterr - set an error condition 995 */ 996 static int /* useless but makes type checking happy */ 997 seterr(struct parse *p, int e) 998 { 999 if (p->error == 0) /* keep earliest error condition */ 1000 p->error = e; 1001 p->next = nuls; /* try to bring things to a halt */ 1002 p->end = nuls; 1003 return(0); /* make the return value well-defined */ 1004 } 1005 1006 /* 1007 - allocset - allocate a set of characters for [] 1008 */ 1009 static cset * 1010 allocset(struct parse *p) 1011 { 1012 int no = p->g->ncsets++; 1013 size_t nc; 1014 size_t nbytes; 1015 cset *cs; 1016 size_t css = (size_t)p->g->csetsize; 1017 int i; 1018 1019 if (no >= p->ncsalloc) { /* need another column of space */ 1020 void *ptr; 1021 1022 p->ncsalloc += CHAR_BIT; 1023 nc = p->ncsalloc; 1024 assert(nc % CHAR_BIT == 0); 1025 nbytes = nc / CHAR_BIT * css; 1026 1027 ptr = (cset *)realloc((char *)p->g->sets, nc * sizeof(cset)); 1028 if (ptr == NULL) 1029 goto nomem; 1030 p->g->sets = ptr; 1031 1032 ptr = (uch *)realloc((char *)p->g->setbits, nbytes); 1033 if (ptr == NULL) 1034 goto nomem; 1035 p->g->setbits = ptr; 1036 1037 for (i = 0; i < no; i++) 1038 p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT); 1039 1040 (void) memset((char *)p->g->setbits + (nbytes - css), 0, css); 1041 } 1042 /* XXX should not happen */ 1043 if (p->g->sets == NULL || p->g->setbits == NULL) 1044 goto nomem; 1045 1046 cs = &p->g->sets[no]; 1047 cs->ptr = p->g->setbits + css*((no)/CHAR_BIT); 1048 cs->mask = 1 << ((no) % CHAR_BIT); 1049 cs->hash = 0; 1050 cs->smultis = 0; 1051 cs->multis = NULL; 1052 1053 return(cs); 1054 nomem: 1055 free(p->g->sets); 1056 p->g->sets = NULL; 1057 free(p->g->setbits); 1058 p->g->setbits = NULL; 1059 1060 SETERROR(REG_ESPACE); 1061 /* caller's responsibility not to do set ops */ 1062 return(NULL); 1063 } 1064 1065 /* 1066 - freeset - free a now-unused set 1067 */ 1068 static void 1069 freeset(struct parse *p, cset *cs) 1070 { 1071 int i; 1072 cset *top = &p->g->sets[p->g->ncsets]; 1073 size_t css = (size_t)p->g->csetsize; 1074 1075 for (i = 0; i < css; i++) 1076 CHsub(cs, i); 1077 if (cs == top-1) /* recover only the easy case */ 1078 p->g->ncsets--; 1079 } 1080 1081 /* 1082 - freezeset - final processing on a set of characters 1083 * 1084 * The main task here is merging identical sets. This is usually a waste 1085 * of time (although the hash code minimizes the overhead), but can win 1086 * big if REG_ICASE is being used. REG_ICASE, by the way, is why the hash 1087 * is done using addition rather than xor -- all ASCII [aA] sets xor to 1088 * the same value! 1089 */ 1090 static int /* set number */ 1091 freezeset(struct parse *p, cset *cs) 1092 { 1093 uch h = cs->hash; 1094 int i; 1095 cset *top = &p->g->sets[p->g->ncsets]; 1096 cset *cs2; 1097 size_t css = (size_t)p->g->csetsize; 1098 1099 /* look for an earlier one which is the same */ 1100 for (cs2 = &p->g->sets[0]; cs2 < top; cs2++) 1101 if (cs2->hash == h && cs2 != cs) { 1102 /* maybe */ 1103 for (i = 0; i < css; i++) 1104 if (!!CHIN(cs2, i) != !!CHIN(cs, i)) 1105 break; /* no */ 1106 if (i == css) 1107 break; /* yes */ 1108 } 1109 1110 if (cs2 < top) { /* found one */ 1111 freeset(p, cs); 1112 cs = cs2; 1113 } 1114 1115 return((int)(cs - p->g->sets)); 1116 } 1117 1118 /* 1119 - firstch - return first character in a set (which must have at least one) 1120 */ 1121 static int /* character; there is no "none" value */ 1122 firstch(struct parse *p, cset *cs) 1123 { 1124 int i; 1125 size_t css = (size_t)p->g->csetsize; 1126 1127 for (i = 0; i < css; i++) 1128 if (CHIN(cs, i)) 1129 return((char)i); 1130 assert(never); 1131 return(0); /* arbitrary */ 1132 } 1133 1134 /* 1135 - nch - number of characters in a set 1136 */ 1137 static int 1138 nch(struct parse *p, cset *cs) 1139 { 1140 int i; 1141 size_t css = (size_t)p->g->csetsize; 1142 int n = 0; 1143 1144 for (i = 0; i < css; i++) 1145 if (CHIN(cs, i)) 1146 n++; 1147 return(n); 1148 } 1149 1150 /* 1151 - mcadd - add a collating element to a cset 1152 */ 1153 static void 1154 mcadd( struct parse *p, cset *cs, char *cp) 1155 { 1156 size_t oldend = cs->smultis; 1157 void *np; 1158 1159 cs->smultis += strlen(cp) + 1; 1160 np = realloc(cs->multis, cs->smultis); 1161 if (np == NULL) { 1162 if (cs->multis) 1163 free(cs->multis); 1164 cs->multis = NULL; 1165 SETERROR(REG_ESPACE); 1166 return; 1167 } 1168 cs->multis = np; 1169 1170 strlcpy(cs->multis + oldend - 1, cp, cs->smultis - oldend + 1); 1171 } 1172 1173 /* 1174 - mcinvert - invert the list of collating elements in a cset 1175 * 1176 * This would have to know the set of possibilities. Implementation 1177 * is deferred. 1178 */ 1179 /* ARGSUSED */ 1180 static void 1181 mcinvert(struct parse *p, cset *cs) 1182 { 1183 assert(cs->multis == NULL); /* xxx */ 1184 } 1185 1186 /* 1187 - mccase - add case counterparts of the list of collating elements in a cset 1188 * 1189 * This would have to know the set of possibilities. Implementation 1190 * is deferred. 1191 */ 1192 /* ARGSUSED */ 1193 static void 1194 mccase(struct parse *p, cset *cs) 1195 { 1196 assert(cs->multis == NULL); /* xxx */ 1197 } 1198 1199 /* 1200 - isinsets - is this character in any sets? 1201 */ 1202 static int /* predicate */ 1203 isinsets(struct re_guts *g, int c) 1204 { 1205 uch *col; 1206 int i; 1207 int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT; 1208 unsigned uc = (uch)c; 1209 1210 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize) 1211 if (col[uc] != 0) 1212 return(1); 1213 return(0); 1214 } 1215 1216 /* 1217 - samesets - are these two characters in exactly the same sets? 1218 */ 1219 static int /* predicate */ 1220 samesets(struct re_guts *g, int c1, int c2) 1221 { 1222 uch *col; 1223 int i; 1224 int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT; 1225 unsigned uc1 = (uch)c1; 1226 unsigned uc2 = (uch)c2; 1227 1228 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize) 1229 if (col[uc1] != col[uc2]) 1230 return(0); 1231 return(1); 1232 } 1233 1234 /* 1235 - categorize - sort out character categories 1236 */ 1237 static void 1238 categorize(struct parse *p, struct re_guts *g) 1239 { 1240 cat_t *cats = g->categories; 1241 int c; 1242 int c2; 1243 cat_t cat; 1244 1245 /* avoid making error situations worse */ 1246 if (p->error != 0) 1247 return; 1248 1249 for (c = CHAR_MIN; c <= CHAR_MAX; c++) 1250 if (cats[c] == 0 && isinsets(g, c)) { 1251 cat = g->ncategories++; 1252 cats[c] = cat; 1253 for (c2 = c+1; c2 <= CHAR_MAX; c2++) 1254 if (cats[c2] == 0 && samesets(g, c, c2)) 1255 cats[c2] = cat; 1256 } 1257 } 1258 1259 /* 1260 - dupl - emit a duplicate of a bunch of sops 1261 */ 1262 static sopno /* start of duplicate */ 1263 dupl(struct parse *p, 1264 sopno start, /* from here */ 1265 sopno finish) /* to this less one */ 1266 { 1267 sopno ret = HERE(); 1268 sopno len = finish - start; 1269 1270 assert(finish >= start); 1271 if (len == 0) 1272 return(ret); 1273 enlarge(p, p->ssize + len); /* this many unexpected additions */ 1274 assert(p->ssize >= p->slen + len); 1275 (void) memcpy((char *)(p->strip + p->slen), 1276 (char *)(p->strip + start), (size_t)len*sizeof(sop)); 1277 p->slen += len; 1278 return(ret); 1279 } 1280 1281 /* 1282 - doemit - emit a strip operator 1283 * 1284 * It might seem better to implement this as a macro with a function as 1285 * hard-case backup, but it's just too big and messy unless there are 1286 * some changes to the data structures. Maybe later. 1287 */ 1288 static void 1289 doemit(struct parse *p, sop op, size_t opnd) 1290 { 1291 /* avoid making error situations worse */ 1292 if (p->error != 0) 1293 return; 1294 1295 /* deal with oversize operands ("can't happen", more or less) */ 1296 assert(opnd < 1<<OPSHIFT); 1297 1298 /* deal with undersized strip */ 1299 if (p->slen >= p->ssize) 1300 enlarge(p, (p->ssize+1) / 2 * 3); /* +50% */ 1301 assert(p->slen < p->ssize); 1302 1303 /* finally, it's all reduced to the easy case */ 1304 p->strip[p->slen++] = SOP(op, opnd); 1305 } 1306 1307 /* 1308 - doinsert - insert a sop into the strip 1309 */ 1310 static void 1311 doinsert(struct parse *p, sop op, size_t opnd, sopno pos) 1312 { 1313 sopno sn; 1314 sop s; 1315 int i; 1316 1317 /* avoid making error situations worse */ 1318 if (p->error != 0) 1319 return; 1320 1321 sn = HERE(); 1322 EMIT(op, opnd); /* do checks, ensure space */ 1323 assert(HERE() == sn+1); 1324 s = p->strip[sn]; 1325 1326 /* adjust paren pointers */ 1327 assert(pos > 0); 1328 for (i = 1; i < NPAREN; i++) { 1329 if (p->pbegin[i] >= pos) { 1330 p->pbegin[i]++; 1331 } 1332 if (p->pend[i] >= pos) { 1333 p->pend[i]++; 1334 } 1335 } 1336 1337 memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos], 1338 (HERE()-pos-1)*sizeof(sop)); 1339 p->strip[pos] = s; 1340 } 1341 1342 /* 1343 - dofwd - complete a forward reference 1344 */ 1345 static void 1346 dofwd(struct parse *p, sopno pos, sop value) 1347 { 1348 /* avoid making error situations worse */ 1349 if (p->error != 0) 1350 return; 1351 1352 assert(value < 1<<OPSHIFT); 1353 p->strip[pos] = OP(p->strip[pos]) | value; 1354 } 1355 1356 /* 1357 - enlarge - enlarge the strip 1358 */ 1359 static void 1360 enlarge(struct parse *p, sopno size) 1361 { 1362 sop *sp; 1363 1364 if (p->ssize >= size) 1365 return; 1366 1367 sp = (sop *)realloc(p->strip, size*sizeof(sop)); 1368 if (sp == NULL) { 1369 SETERROR(REG_ESPACE); 1370 return; 1371 } 1372 p->strip = sp; 1373 p->ssize = size; 1374 } 1375 1376 /* 1377 - stripsnug - compact the strip 1378 */ 1379 static void 1380 stripsnug(struct parse *p, struct re_guts *g) 1381 { 1382 g->nstates = p->slen; 1383 g->strip = (sop *)realloc((char *)p->strip, p->slen * sizeof(sop)); 1384 if (g->strip == NULL) { 1385 SETERROR(REG_ESPACE); 1386 g->strip = p->strip; 1387 } 1388 } 1389 1390 /* 1391 - findmust - fill in must and mlen with longest mandatory literal string 1392 * 1393 * This algorithm could do fancy things like analyzing the operands of | 1394 * for common subsequences. Someday. This code is simple and finds most 1395 * of the interesting cases. 1396 * 1397 * Note that must and mlen got initialized during setup. 1398 */ 1399 static void 1400 findmust(struct parse *p, struct re_guts *g) 1401 { 1402 sop *scan; 1403 sop *start; /* start initialized in the default case, after that */ 1404 sop *newstart; /* newstart was initialized in the OCHAR case */ 1405 sopno newlen; 1406 sop s; 1407 char *cp; 1408 sopno i; 1409 1410 /* avoid making error situations worse */ 1411 if (p->error != 0) 1412 return; 1413 1414 /* find the longest OCHAR sequence in strip */ 1415 newlen = 0; 1416 scan = g->strip + 1; 1417 do { 1418 s = *scan++; 1419 switch (OP(s)) { 1420 case OCHAR: /* sequence member */ 1421 if (newlen == 0) /* new sequence */ 1422 newstart = scan - 1; 1423 newlen++; 1424 break; 1425 case OPLUS_: /* things that don't break one */ 1426 case OLPAREN: 1427 case ORPAREN: 1428 break; 1429 case OQUEST_: /* things that must be skipped */ 1430 case OCH_: 1431 scan--; 1432 do { 1433 scan += OPND(s); 1434 s = *scan; 1435 /* assert() interferes w debug printouts */ 1436 if (OP(s) != O_QUEST && OP(s) != O_CH && 1437 OP(s) != OOR2) { 1438 g->iflags |= BAD; 1439 return; 1440 } 1441 } while (OP(s) != O_QUEST && OP(s) != O_CH); 1442 /* fallthrough */ 1443 default: /* things that break a sequence */ 1444 if (newlen > g->mlen) { /* ends one */ 1445 start = newstart; 1446 g->mlen = newlen; 1447 } 1448 newlen = 0; 1449 break; 1450 } 1451 } while (OP(s) != OEND); 1452 1453 if (g->mlen == 0) /* there isn't one */ 1454 return; 1455 1456 /* turn it into a character string */ 1457 g->must = malloc((size_t)g->mlen + 1); 1458 if (g->must == NULL) { /* argh; just forget it */ 1459 g->mlen = 0; 1460 return; 1461 } 1462 cp = g->must; 1463 scan = start; 1464 for (i = g->mlen; i > 0; i--) { 1465 while (OP(s = *scan++) != OCHAR) 1466 continue; 1467 assert(cp < g->must + g->mlen); 1468 *cp++ = (char)OPND(s); 1469 } 1470 assert(cp == g->must + g->mlen); 1471 *cp++ = '\0'; /* just on general principles */ 1472 } 1473 1474 /* 1475 - pluscount - count + nesting 1476 */ 1477 static sopno /* nesting depth */ 1478 pluscount(struct parse *p, struct re_guts *g) 1479 { 1480 sop *scan; 1481 sop s; 1482 sopno plusnest = 0; 1483 sopno maxnest = 0; 1484 1485 if (p->error != 0) 1486 return(0); /* there may not be an OEND */ 1487 1488 scan = g->strip + 1; 1489 do { 1490 s = *scan++; 1491 switch (OP(s)) { 1492 case OPLUS_: 1493 plusnest++; 1494 break; 1495 case O_PLUS: 1496 if (plusnest > maxnest) 1497 maxnest = plusnest; 1498 plusnest--; 1499 break; 1500 } 1501 } while (OP(s) != OEND); 1502 if (plusnest != 0) 1503 g->iflags |= BAD; 1504 return(maxnest); 1505 } 1506