1/* $OpenBSD: regcomp.c,v 1.19 2008/02/23 08:13:07 otto 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 */ 55struct 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 69static void p_ere(struct parse *, int); 70static void p_ere_exp(struct parse *); 71static void p_str(struct parse *); 72static void p_bre(struct parse *, int, int); 73static int p_simp_re(struct parse *, int); 74static int p_count(struct parse *); 75static void p_bracket(struct parse *); 76static void p_b_term(struct parse *, cset *); 77static void p_b_cclass(struct parse *, cset *); 78static void p_b_eclass(struct parse *, cset *); 79static char p_b_symbol(struct parse *); 80static char p_b_coll_elem(struct parse *, int); 81static char othercase(int); 82static void bothcases(struct parse *, int); 83static void ordinary(struct parse *, int); 84static void nonnewline(struct parse *); 85static void repeat(struct parse *, sopno, int, int); 86static int seterr(struct parse *, int); 87static cset *allocset(struct parse *); 88static void freeset(struct parse *, cset *); 89static int freezeset(struct parse *, cset *); 90static int firstch(struct parse *, cset *); 91static int nch(struct parse *, cset *); 92static void mcadd(struct parse *, cset *, const char *); 93static void mcinvert(struct parse *, cset *); 94static void mccase(struct parse *, cset *); 95static int isinsets(struct re_guts *, int); 96static int samesets(struct re_guts *, int, int); 97static void categorize(struct parse *, struct re_guts *); 98static sopno dupl(struct parse *, sopno, sopno); 99static void doemit(struct parse *, sop, size_t); 100static void doinsert(struct parse *, sop, size_t, sopno); 101static void dofwd(struct parse *, sopno, sop); 102static void enlarge(struct parse *, sopno); 103static void stripsnug(struct parse *, struct re_guts *); 104static void findmust(struct parse *, struct re_guts *); 105static sopno pluscount(struct parse *, struct re_guts *); 106 107static 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) if (!(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 140static 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 */ 148int /* 0 success, otherwise REG_something */ 149regcomp(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 */ 248static void 249p_ere(struct parse *p, int stop) /* character this ERE should end at */ 250{ 251 char c; 252 sopno prevback = 0; 253 sopno prevfwd = 0; 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 */ 291static void 292p_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#ifndef POSIX_MISTAKE 323 case ')': /* happens only if no current unmatched ( */ 324 /* 325 * You may ask, why the ifndef? Because I didn't notice 326 * this until slightly too late for 1003.2, and none of the 327 * other 1003.2 regular-expression reviewers noticed it at 328 * all. So an unmatched ) is legal POSIX, at least until 329 * we can get it fixed. 330 */ 331 SETERROR(REG_EPAREN); 332 break; 333#endif 334 case '^': 335 EMIT(OBOL, 0); 336 p->g->iflags |= USEBOL; 337 p->g->nbol++; 338 wascaret = 1; 339 break; 340 case '$': 341 EMIT(OEOL, 0); 342 p->g->iflags |= USEEOL; 343 p->g->neol++; 344 break; 345 case '|': 346 SETERROR(REG_EMPTY); 347 break; 348 case '*': 349 case '+': 350 case '?': 351 SETERROR(REG_BADRPT); 352 break; 353 case '.': 354 if (p->g->cflags®_NEWLINE) 355 nonnewline(p); 356 else 357 EMIT(OANY, 0); 358 break; 359 case '[': 360 p_bracket(p); 361 break; 362 case '\\': 363 REQUIRE(MORE(), REG_EESCAPE); 364 c = GETNEXT(); 365 ordinary(p, c); 366 break; 367 case '{': /* okay as ordinary except if digit follows */ 368 REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT); 369 /* FALLTHROUGH */ 370 default: 371 ordinary(p, c); 372 break; 373 } 374 375 if (!MORE()) 376 return; 377 c = PEEK(); 378 /* we call { a repetition if followed by a digit */ 379 if (!( c == '*' || c == '+' || c == '?' || 380 (c == '{' && MORE2() && isdigit((uch)PEEK2())) )) 381 return; /* no repetition, we're done */ 382 NEXT(); 383 384 REQUIRE(!wascaret, REG_BADRPT); 385 switch (c) { 386 case '*': /* implemented as +? */ 387 /* this case does not require the (y|) trick, noKLUDGE */ 388 INSERT(OPLUS_, pos); 389 ASTERN(O_PLUS, pos); 390 INSERT(OQUEST_, pos); 391 ASTERN(O_QUEST, pos); 392 break; 393 case '+': 394 INSERT(OPLUS_, pos); 395 ASTERN(O_PLUS, pos); 396 break; 397 case '?': 398 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */ 399 INSERT(OCH_, pos); /* offset slightly wrong */ 400 ASTERN(OOR1, pos); /* this one's right */ 401 AHEAD(pos); /* fix the OCH_ */ 402 EMIT(OOR2, 0); /* offset very wrong... */ 403 AHEAD(THERE()); /* ...so fix it */ 404 ASTERN(O_CH, THERETHERE()); 405 break; 406 case '{': 407 count = p_count(p); 408 if (EAT(',')) { 409 if (isdigit((uch)PEEK())) { 410 count2 = p_count(p); 411 REQUIRE(count <= count2, REG_BADBR); 412 } else /* single number with comma */ 413 count2 = INFINITY; 414 } else /* just a single number */ 415 count2 = count; 416 repeat(p, pos, count, count2); 417 if (!EAT('}')) { /* error heuristics */ 418 while (MORE() && PEEK() != '}') 419 NEXT(); 420 REQUIRE(MORE(), REG_EBRACE); 421 SETERROR(REG_BADBR); 422 } 423 break; 424 } 425 426 if (!MORE()) 427 return; 428 c = PEEK(); 429 if (!( c == '*' || c == '+' || c == '?' || 430 (c == '{' && MORE2() && isdigit((uch)PEEK2())) ) ) 431 return; 432 SETERROR(REG_BADRPT); 433} 434 435/* 436 - p_str - string (no metacharacters) "parser" 437 */ 438static void 439p_str(struct parse *p) 440{ 441 REQUIRE(MORE(), REG_EMPTY); 442 while (MORE()) 443 ordinary(p, GETNEXT()); 444} 445 446/* 447 - p_bre - BRE parser top level, anchoring and concatenation 448 * Giving end1 as OUT essentially eliminates the end1/end2 check. 449 * 450 * This implementation is a bit of a kludge, in that a trailing $ is first 451 * taken as an ordinary character and then revised to be an anchor. The 452 * only undesirable side effect is that '$' gets included as a character 453 * category in such cases. This is fairly harmless; not worth fixing. 454 * The amount of lookahead needed to avoid this kludge is excessive. 455 */ 456static void 457p_bre(struct parse *p, 458 int end1, /* first terminating character */ 459 int end2) /* second terminating character */ 460{ 461 sopno start = HERE(); 462 int first = 1; /* first subexpression? */ 463 int wasdollar = 0; 464 465 if (EAT('^')) { 466 EMIT(OBOL, 0); 467 p->g->iflags |= USEBOL; 468 p->g->nbol++; 469 } 470 while (MORE() && !SEETWO(end1, end2)) { 471 wasdollar = p_simp_re(p, first); 472 first = 0; 473 } 474 if (wasdollar) { /* oops, that was a trailing anchor */ 475 DROP(1); 476 EMIT(OEOL, 0); 477 p->g->iflags |= USEEOL; 478 p->g->neol++; 479 } 480 481 REQUIRE(HERE() != start, REG_EMPTY); /* require nonempty */ 482} 483 484/* 485 - p_simp_re - parse a simple RE, an atom possibly followed by a repetition 486 */ 487static int /* was the simple RE an unbackslashed $? */ 488p_simp_re(struct parse *p, 489 int starordinary) /* is a leading * an ordinary character? */ 490{ 491 int c; 492 int count; 493 int count2; 494 sopno pos; 495 int i; 496 sopno subno; 497# define BACKSL (1<<CHAR_BIT) 498 499 pos = HERE(); /* repetion op, if any, covers from here */ 500 501 assert(MORE()); /* caller should have ensured this */ 502 c = GETNEXT(); 503 if (c == '\\') { 504 REQUIRE(MORE(), REG_EESCAPE); 505 c = BACKSL | GETNEXT(); 506 } 507 switch (c) { 508 case '.': 509 if (p->g->cflags®_NEWLINE) 510 nonnewline(p); 511 else 512 EMIT(OANY, 0); 513 break; 514 case '[': 515 p_bracket(p); 516 break; 517 case BACKSL|'{': 518 SETERROR(REG_BADRPT); 519 break; 520 case BACKSL|'(': 521 p->g->nsub++; 522 subno = p->g->nsub; 523 if (subno < NPAREN) 524 p->pbegin[subno] = HERE(); 525 EMIT(OLPAREN, subno); 526 /* the MORE here is an error heuristic */ 527 if (MORE() && !SEETWO('\\', ')')) 528 p_bre(p, '\\', ')'); 529 if (subno < NPAREN) { 530 p->pend[subno] = HERE(); 531 assert(p->pend[subno] != 0); 532 } 533 EMIT(ORPAREN, subno); 534 REQUIRE(EATTWO('\\', ')'), REG_EPAREN); 535 break; 536 case BACKSL|')': /* should not get here -- must be user */ 537 case BACKSL|'}': 538 SETERROR(REG_EPAREN); 539 break; 540 case BACKSL|'1': 541 case BACKSL|'2': 542 case BACKSL|'3': 543 case BACKSL|'4': 544 case BACKSL|'5': 545 case BACKSL|'6': 546 case BACKSL|'7': 547 case BACKSL|'8': 548 case BACKSL|'9': 549 i = (c&~BACKSL) - '0'; 550 assert(i < NPAREN); 551 if (p->pend[i] != 0) { 552 assert(i <= p->g->nsub); 553 EMIT(OBACK_, i); 554 assert(p->pbegin[i] != 0); 555 assert(OP(p->strip[p->pbegin[i]]) == OLPAREN); 556 assert(OP(p->strip[p->pend[i]]) == ORPAREN); 557 (void) dupl(p, p->pbegin[i]+1, p->pend[i]); 558 EMIT(O_BACK, i); 559 } else 560 SETERROR(REG_ESUBREG); 561 p->g->backrefs = 1; 562 break; 563 case '*': 564 REQUIRE(starordinary, REG_BADRPT); 565 /* FALLTHROUGH */ 566 default: 567 ordinary(p, (char)c); 568 break; 569 } 570 571 if (EAT('*')) { /* implemented as +? */ 572 /* this case does not require the (y|) trick, noKLUDGE */ 573 INSERT(OPLUS_, pos); 574 ASTERN(O_PLUS, pos); 575 INSERT(OQUEST_, pos); 576 ASTERN(O_QUEST, pos); 577 } else if (EATTWO('\\', '{')) { 578 count = p_count(p); 579 if (EAT(',')) { 580 if (MORE() && isdigit((uch)PEEK())) { 581 count2 = p_count(p); 582 REQUIRE(count <= count2, REG_BADBR); 583 } else /* single number with comma */ 584 count2 = INFINITY; 585 } else /* just a single number */ 586 count2 = count; 587 repeat(p, pos, count, count2); 588 if (!EATTWO('\\', '}')) { /* error heuristics */ 589 while (MORE() && !SEETWO('\\', '}')) 590 NEXT(); 591 REQUIRE(MORE(), REG_EBRACE); 592 SETERROR(REG_BADBR); 593 } 594 } else if (c == '$') /* $ (but not \$) ends it */ 595 return(1); 596 597 return(0); 598} 599 600/* 601 - p_count - parse a repetition count 602 */ 603static int /* the value */ 604p_count(struct parse *p) 605{ 606 int count = 0; 607 int ndigits = 0; 608 609 while (MORE() && isdigit((uch)PEEK()) && count <= DUPMAX) { 610 count = count*10 + (GETNEXT() - '0'); 611 ndigits++; 612 } 613 614 REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR); 615 return(count); 616} 617 618/* 619 - p_bracket - parse a bracketed character list 620 * 621 * Note a significant property of this code: if the allocset() did SETERROR, 622 * no set operations are done. 623 */ 624static void 625p_bracket(struct parse *p) 626{ 627 cset *cs; 628 int invert = 0; 629 630 /* Dept of Truly Sickening Special-Case Kludges */ 631 if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) { 632 EMIT(OBOW, 0); 633 NEXTn(6); 634 return; 635 } 636 if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) { 637 EMIT(OEOW, 0); 638 NEXTn(6); 639 return; 640 } 641 642 if ((cs = allocset(p)) == NULL) { 643 /* allocset did set error status in p */ 644 return; 645 } 646 647 if (EAT('^')) 648 invert++; /* make note to invert set at end */ 649 if (EAT(']')) 650 CHadd(cs, ']'); 651 else if (EAT('-')) 652 CHadd(cs, '-'); 653 while (MORE() && PEEK() != ']' && !SEETWO('-', ']')) 654 p_b_term(p, cs); 655 if (EAT('-')) 656 CHadd(cs, '-'); 657 MUSTEAT(']', REG_EBRACK); 658 659 if (p->error != 0) { /* don't mess things up further */ 660 freeset(p, cs); 661 return; 662 } 663 664 if (p->g->cflags®_ICASE) { 665 int i; 666 int ci; 667 668 for (i = p->g->csetsize - 1; i >= 0; i--) 669 if (CHIN(cs, i) && isalpha(i)) { 670 ci = othercase(i); 671 if (ci != i) 672 CHadd(cs, ci); 673 } 674 if (cs->multis != NULL) 675 mccase(p, cs); 676 } 677 if (invert) { 678 int i; 679 680 for (i = p->g->csetsize - 1; i >= 0; i--) 681 if (CHIN(cs, i)) 682 CHsub(cs, i); 683 else 684 CHadd(cs, i); 685 if (p->g->cflags®_NEWLINE) 686 CHsub(cs, '\n'); 687 if (cs->multis != NULL) 688 mcinvert(p, cs); 689 } 690 691 assert(cs->multis == NULL); /* xxx */ 692 693 if (nch(p, cs) == 1) { /* optimize singleton sets */ 694 ordinary(p, firstch(p, cs)); 695 freeset(p, cs); 696 } else 697 EMIT(OANYOF, freezeset(p, cs)); 698} 699 700/* 701 - p_b_term - parse one term of a bracketed character list 702 */ 703static void 704p_b_term(struct parse *p, cset *cs) 705{ 706 char c; 707 char start, finish; 708 int i; 709 710 /* classify what we've got */ 711 switch ((MORE()) ? PEEK() : '\0') { 712 case '[': 713 c = (MORE2()) ? PEEK2() : '\0'; 714 break; 715 case '-': 716 SETERROR(REG_ERANGE); 717 return; /* NOTE RETURN */ 718 break; 719 default: 720 c = '\0'; 721 break; 722 } 723 724 switch (c) { 725 case ':': /* character class */ 726 NEXT2(); 727 REQUIRE(MORE(), REG_EBRACK); 728 c = PEEK(); 729 REQUIRE(c != '-' && c != ']', REG_ECTYPE); 730 p_b_cclass(p, cs); 731 REQUIRE(MORE(), REG_EBRACK); 732 REQUIRE(EATTWO(':', ']'), REG_ECTYPE); 733 break; 734 case '=': /* equivalence class */ 735 NEXT2(); 736 REQUIRE(MORE(), REG_EBRACK); 737 c = PEEK(); 738 REQUIRE(c != '-' && c != ']', REG_ECOLLATE); 739 p_b_eclass(p, cs); 740 REQUIRE(MORE(), REG_EBRACK); 741 REQUIRE(EATTWO('=', ']'), REG_ECOLLATE); 742 break; 743 default: /* symbol, ordinary character, or range */ 744/* xxx revision needed for multichar stuff */ 745 start = p_b_symbol(p); 746 if (SEE('-') && MORE2() && PEEK2() != ']') { 747 /* range */ 748 NEXT(); 749 if (EAT('-')) 750 finish = '-'; 751 else 752 finish = p_b_symbol(p); 753 } else 754 finish = start; 755/* xxx what about signed chars here... */ 756 REQUIRE(start <= finish, REG_ERANGE); 757 for (i = start; i <= finish; i++) 758 CHadd(cs, i); 759 break; 760 } 761} 762 763/* 764 - p_b_cclass - parse a character-class name and deal with it 765 */ 766static void 767p_b_cclass(struct parse *p, cset *cs) 768{ 769 char *sp = p->next; 770 const struct cclass *cp; 771 size_t len; 772 const char *u; 773 char c; 774 775 while (MORE() && isalpha(PEEK())) 776 NEXT(); 777 len = p->next - sp; 778 for (cp = cclasses; cp->name != NULL; cp++) 779 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0') 780 break; 781 if (cp->name == NULL) { 782 /* oops, didn't find it */ 783 SETERROR(REG_ECTYPE); 784 return; 785 } 786 787 u = cp->chars; 788 while ((c = *u++) != '\0') 789 CHadd(cs, c); 790 for (u = cp->multis; *u != '\0'; u += strlen(u) + 1) 791 MCadd(p, cs, u); 792} 793 794/* 795 - p_b_eclass - parse an equivalence-class name and deal with it 796 * 797 * This implementation is incomplete. xxx 798 */ 799static void 800p_b_eclass(struct parse *p, cset *cs) 801{ 802 char c; 803 804 c = p_b_coll_elem(p, '='); 805 CHadd(cs, c); 806} 807 808/* 809 - p_b_symbol - parse a character or [..]ed multicharacter collating symbol 810 */ 811static char /* value of symbol */ 812p_b_symbol(struct parse *p) 813{ 814 char value; 815 816 REQUIRE(MORE(), REG_EBRACK); 817 if (!EATTWO('[', '.')) 818 return(GETNEXT()); 819 820 /* collating symbol */ 821 value = p_b_coll_elem(p, '.'); 822 REQUIRE(EATTWO('.', ']'), REG_ECOLLATE); 823 return(value); 824} 825 826/* 827 - p_b_coll_elem - parse a collating-element name and look it up 828 */ 829static char /* value of collating element */ 830p_b_coll_elem(struct parse *p, 831 int endc) /* name ended by endc,']' */ 832{ 833 char *sp = p->next; 834 const struct cname *cp; 835 int len; 836 837 while (MORE() && !SEETWO(endc, ']')) 838 NEXT(); 839 if (!MORE()) { 840 SETERROR(REG_EBRACK); 841 return(0); 842 } 843 len = p->next - sp; 844 for (cp = cnames; cp->name != NULL; cp++) 845 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0') 846 return(cp->code); /* known name */ 847 if (len == 1) 848 return(*sp); /* single character */ 849 SETERROR(REG_ECOLLATE); /* neither */ 850 return(0); 851} 852 853/* 854 - othercase - return the case counterpart of an alphabetic 855 */ 856static char /* if no counterpart, return ch */ 857othercase(int ch) 858{ 859 ch = (uch)ch; 860 assert(isalpha(ch)); 861 if (isupper(ch)) 862 return ((uch)tolower(ch)); 863 else if (islower(ch)) 864 return ((uch)toupper(ch)); 865 else /* peculiar, but could happen */ 866 return(ch); 867} 868 869/* 870 - bothcases - emit a dualcase version of a two-case character 871 * 872 * Boy, is this implementation ever a kludge... 873 */ 874static void 875bothcases(struct parse *p, int ch) 876{ 877 char *oldnext = p->next; 878 char *oldend = p->end; 879 char bracket[3]; 880 881 ch = (uch)ch; 882 assert(othercase(ch) != ch); /* p_bracket() would recurse */ 883 p->next = bracket; 884 p->end = bracket+2; 885 bracket[0] = ch; 886 bracket[1] = ']'; 887 bracket[2] = '\0'; 888 p_bracket(p); 889 assert(p->next == bracket+2); 890 p->next = oldnext; 891 p->end = oldend; 892} 893 894/* 895 - ordinary - emit an ordinary character 896 */ 897static void 898ordinary(struct parse *p, int ch) 899{ 900 cat_t *cap = p->g->categories; 901 902 if ((p->g->cflags®_ICASE) && isalpha((uch)ch) && othercase(ch) != ch) 903 bothcases(p, ch); 904 else { 905 EMIT(OCHAR, (uch)ch); 906 if (cap[ch] == 0) 907 cap[ch] = p->g->ncategories++; 908 } 909} 910 911/* 912 - nonnewline - emit REG_NEWLINE version of OANY 913 * 914 * Boy, is this implementation ever a kludge... 915 */ 916static void 917nonnewline(struct parse *p) 918{ 919 char *oldnext = p->next; 920 char *oldend = p->end; 921 char bracket[4]; 922 923 p->next = bracket; 924 p->end = bracket+3; 925 bracket[0] = '^'; 926 bracket[1] = '\n'; 927 bracket[2] = ']'; 928 bracket[3] = '\0'; 929 p_bracket(p); 930 assert(p->next == bracket+3); 931 p->next = oldnext; 932 p->end = oldend; 933} 934 935/* 936 - repeat - generate code for a bounded repetition, recursively if needed 937 */ 938static void 939repeat(struct parse *p, 940 sopno start, /* operand from here to end of strip */ 941 int from, /* repeated from this number */ 942 int to) /* to this number of times (maybe INFINITY) */ 943{ 944 sopno finish = HERE(); 945# define N 2 946# define INF 3 947# define REP(f, t) ((f)*8 + (t)) 948# define MAP(n) (((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N) 949 sopno copy; 950 951 if (p->error != 0) /* head off possible runaway recursion */ 952 return; 953 954 assert(from <= to); 955 956 switch (REP(MAP(from), MAP(to))) { 957 case REP(0, 0): /* must be user doing this */ 958 DROP(finish-start); /* drop the operand */ 959 break; 960 case REP(0, 1): /* as x{1,1}? */ 961 case REP(0, N): /* as x{1,n}? */ 962 case REP(0, INF): /* as x{1,}? */ 963 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */ 964 INSERT(OCH_, start); /* offset is wrong... */ 965 repeat(p, start+1, 1, to); 966 ASTERN(OOR1, start); 967 AHEAD(start); /* ... fix it */ 968 EMIT(OOR2, 0); 969 AHEAD(THERE()); 970 ASTERN(O_CH, THERETHERE()); 971 break; 972 case REP(1, 1): /* trivial case */ 973 /* done */ 974 break; 975 case REP(1, N): /* as x?x{1,n-1} */ 976 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */ 977 INSERT(OCH_, start); 978 ASTERN(OOR1, start); 979 AHEAD(start); 980 EMIT(OOR2, 0); /* offset very wrong... */ 981 AHEAD(THERE()); /* ...so fix it */ 982 ASTERN(O_CH, THERETHERE()); 983 copy = dupl(p, start+1, finish+1); 984 assert(copy == finish+4); 985 repeat(p, copy, 1, to-1); 986 break; 987 case REP(1, INF): /* as x+ */ 988 INSERT(OPLUS_, start); 989 ASTERN(O_PLUS, start); 990 break; 991 case REP(N, N): /* as xx{m-1,n-1} */ 992 copy = dupl(p, start, finish); 993 repeat(p, copy, from-1, to-1); 994 break; 995 case REP(N, INF): /* as xx{n-1,INF} */ 996 copy = dupl(p, start, finish); 997 repeat(p, copy, from-1, to); 998 break; 999 default: /* "can't happen" */ 1000 SETERROR(REG_ASSERT); /* just in case */ 1001 break; 1002 } 1003} 1004 1005/* 1006 - seterr - set an error condition 1007 */ 1008static int /* useless but makes type checking happy */ 1009seterr(struct parse *p, int e) 1010{ 1011 if (p->error == 0) /* keep earliest error condition */ 1012 p->error = e; 1013 p->next = nuls; /* try to bring things to a halt */ 1014 p->end = nuls; 1015 return(0); /* make the return value well-defined */ 1016} 1017 1018/* 1019 - allocset - allocate a set of characters for [] 1020 */ 1021static cset * 1022allocset(struct parse *p) 1023{ 1024 int no = p->g->ncsets++; 1025 size_t nc; 1026 size_t nbytes; 1027 cset *cs; 1028 size_t css = (size_t)p->g->csetsize; 1029 int i; 1030 1031 if (no >= p->ncsalloc) { /* need another column of space */ 1032 void *ptr; 1033 1034 p->ncsalloc += CHAR_BIT; 1035 nc = p->ncsalloc; 1036 assert(nc % CHAR_BIT == 0); 1037 nbytes = nc / CHAR_BIT * css; 1038 1039 ptr = (cset *)realloc((char *)p->g->sets, nc * sizeof(cset)); 1040 if (ptr == NULL) 1041 goto nomem; 1042 p->g->sets = (cset*)ptr; 1043 1044 ptr = (uch *)realloc((char *)p->g->setbits, nbytes); 1045 if (ptr == NULL) 1046 goto nomem; 1047 p->g->setbits = (uch*)ptr; 1048 1049 for (i = 0; i < no; i++) 1050 p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT); 1051 1052 (void) memset((char *)p->g->setbits + (nbytes - css), 0, css); 1053 } 1054 /* XXX should not happen */ 1055 if (p->g->sets == NULL || p->g->setbits == NULL) 1056 goto nomem; 1057 1058 cs = &p->g->sets[no]; 1059 cs->ptr = p->g->setbits + css*((no)/CHAR_BIT); 1060 cs->mask = 1 << ((no) % CHAR_BIT); 1061 cs->hash = 0; 1062 cs->smultis = 0; 1063 cs->multis = NULL; 1064 1065 return(cs); 1066nomem: 1067 free(p->g->sets); 1068 p->g->sets = NULL; 1069 free(p->g->setbits); 1070 p->g->setbits = NULL; 1071 1072 SETERROR(REG_ESPACE); 1073 /* caller's responsibility not to do set ops */ 1074 return(NULL); 1075} 1076 1077/* 1078 - freeset - free a now-unused set 1079 */ 1080static void 1081freeset(struct parse *p, cset *cs) 1082{ 1083 int i; 1084 cset *top = &p->g->sets[p->g->ncsets]; 1085 size_t css = (size_t)p->g->csetsize; 1086 1087 for (i = 0; i < (ssize_t)css; i++) 1088 CHsub(cs, i); 1089 if (cs == top-1) /* recover only the easy case */ 1090 p->g->ncsets--; 1091} 1092 1093/* 1094 - freezeset - final processing on a set of characters 1095 * 1096 * The main task here is merging identical sets. This is usually a waste 1097 * of time (although the hash code minimizes the overhead), but can win 1098 * big if REG_ICASE is being used. REG_ICASE, by the way, is why the hash 1099 * is done using addition rather than xor -- all ASCII [aA] sets xor to 1100 * the same value! 1101 */ 1102static int /* set number */ 1103freezeset(struct parse *p, cset *cs) 1104{ 1105 uch h = cs->hash; 1106 int i; 1107 cset *top = &p->g->sets[p->g->ncsets]; 1108 cset *cs2; 1109 size_t css = (size_t)p->g->csetsize; 1110 1111 /* look for an earlier one which is the same */ 1112 for (cs2 = &p->g->sets[0]; cs2 < top; cs2++) 1113 if (cs2->hash == h && cs2 != cs) { 1114 /* maybe */ 1115 for (i = 0; i < (ssize_t)css; i++) 1116 if (!!CHIN(cs2, i) != !!CHIN(cs, i)) 1117 break; /* no */ 1118 if (i == (ssize_t)css) 1119 break; /* yes */ 1120 } 1121 1122 if (cs2 < top) { /* found one */ 1123 freeset(p, cs); 1124 cs = cs2; 1125 } 1126 1127 return((int)(cs - p->g->sets)); 1128} 1129 1130/* 1131 - firstch - return first character in a set (which must have at least one) 1132 */ 1133static int /* character; there is no "none" value */ 1134firstch(struct parse *p, cset *cs) 1135{ 1136 int i; 1137 size_t css = (size_t)p->g->csetsize; 1138 1139 for (i = 0; i < (ssize_t)css; i++) 1140 if (CHIN(cs, i)) 1141 return((char)i); 1142 assert(never); 1143 return(0); /* arbitrary */ 1144} 1145 1146/* 1147 - nch - number of characters in a set 1148 */ 1149static int 1150nch(struct parse *p, cset *cs) 1151{ 1152 int i; 1153 size_t css = (size_t)p->g->csetsize; 1154 int n = 0; 1155 1156 for (i = 0; i < (ssize_t)css; i++) 1157 if (CHIN(cs, i)) 1158 n++; 1159 return(n); 1160} 1161 1162/* 1163 - mcadd - add a collating element to a cset 1164 */ 1165static void 1166mcadd( struct parse *p, cset *cs, const char *cp) 1167{ 1168 size_t oldend = cs->smultis; 1169 void *np; 1170 1171 cs->smultis += strlen(cp) + 1; 1172 np = realloc(cs->multis, cs->smultis); 1173 if (np == NULL) { 1174 if (cs->multis) 1175 free(cs->multis); 1176 cs->multis = NULL; 1177 SETERROR(REG_ESPACE); 1178 return; 1179 } 1180 cs->multis = (char*)np; 1181 1182 strncpy(cs->multis + oldend - 1, cp, cs->smultis - oldend + 1); 1183} 1184 1185/* 1186 - mcinvert - invert the list of collating elements in a cset 1187 * 1188 * This would have to know the set of possibilities. Implementation 1189 * is deferred. 1190 */ 1191/* ARGSUSED */ 1192static void 1193mcinvert(struct parse *p, cset *cs) 1194{ 1195 assert(cs->multis == NULL); /* xxx */ 1196} 1197 1198/* 1199 - mccase - add case counterparts of the list of collating elements in a cset 1200 * 1201 * This would have to know the set of possibilities. Implementation 1202 * is deferred. 1203 */ 1204/* ARGSUSED */ 1205static void 1206mccase(struct parse *p, cset *cs) 1207{ 1208 assert(cs->multis == NULL); /* xxx */ 1209} 1210 1211/* 1212 - isinsets - is this character in any sets? 1213 */ 1214static int /* predicate */ 1215isinsets(struct re_guts *g, int c) 1216{ 1217 uch *col; 1218 int i; 1219 int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT; 1220 unsigned uc = (uch)c; 1221 1222 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize) 1223 if (col[uc] != 0) 1224 return(1); 1225 return(0); 1226} 1227 1228/* 1229 - samesets - are these two characters in exactly the same sets? 1230 */ 1231static int /* predicate */ 1232samesets(struct re_guts *g, int c1, int c2) 1233{ 1234 uch *col; 1235 int i; 1236 int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT; 1237 unsigned uc1 = (uch)c1; 1238 unsigned uc2 = (uch)c2; 1239 1240 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize) 1241 if (col[uc1] != col[uc2]) 1242 return(0); 1243 return(1); 1244} 1245 1246/* 1247 - categorize - sort out character categories 1248 */ 1249static void 1250categorize(struct parse *p, struct re_guts *g) 1251{ 1252 cat_t *cats = g->categories; 1253 int c; 1254 int c2; 1255 cat_t cat; 1256 1257 /* avoid making error situations worse */ 1258 if (p->error != 0) 1259 return; 1260 1261 for (c = CHAR_MIN; c <= CHAR_MAX; c++) 1262 if (cats[c] == 0 && isinsets(g, c)) { 1263 cat = g->ncategories++; 1264 cats[c] = cat; 1265 for (c2 = c+1; c2 <= CHAR_MAX; c2++) 1266 if (cats[c2] == 0 && samesets(g, c, c2)) 1267 cats[c2] = cat; 1268 } 1269} 1270 1271/* 1272 - dupl - emit a duplicate of a bunch of sops 1273 */ 1274static sopno /* start of duplicate */ 1275dupl(struct parse *p, 1276 sopno start, /* from here */ 1277 sopno finish) /* to this less one */ 1278{ 1279 sopno ret = HERE(); 1280 sopno len = finish - start; 1281 1282 assert(finish >= start); 1283 if (len == 0) 1284 return(ret); 1285 enlarge(p, p->ssize + len); /* this many unexpected additions */ 1286 assert(p->ssize >= p->slen + len); 1287 (void) memcpy((char *)(p->strip + p->slen), 1288 (char *)(p->strip + start), (size_t)len*sizeof(sop)); 1289 p->slen += len; 1290 return(ret); 1291} 1292 1293/* 1294 - doemit - emit a strip operator 1295 * 1296 * It might seem better to implement this as a macro with a function as 1297 * hard-case backup, but it's just too big and messy unless there are 1298 * some changes to the data structures. Maybe later. 1299 */ 1300static void 1301doemit(struct parse *p, sop op, size_t opnd) 1302{ 1303 /* avoid making error situations worse */ 1304 if (p->error != 0) 1305 return; 1306 1307 /* deal with oversize operands ("can't happen", more or less) */ 1308 assert(opnd < 1<<OPSHIFT); 1309 1310 /* deal with undersized strip */ 1311 if (p->slen >= p->ssize) 1312 enlarge(p, (p->ssize+1) / 2 * 3); /* +50% */ 1313 assert(p->slen < p->ssize); 1314 1315 /* finally, it's all reduced to the easy case */ 1316 p->strip[p->slen++] = SOP(op, opnd); 1317} 1318 1319/* 1320 - doinsert - insert a sop into the strip 1321 */ 1322static void 1323doinsert(struct parse *p, sop op, size_t opnd, sopno pos) 1324{ 1325 sopno sn; 1326 sop s; 1327 int i; 1328 1329 /* avoid making error situations worse */ 1330 if (p->error != 0) 1331 return; 1332 1333 sn = HERE(); 1334 EMIT(op, opnd); /* do checks, ensure space */ 1335 assert(HERE() == sn+1); 1336 s = p->strip[sn]; 1337 1338 /* adjust paren pointers */ 1339 assert(pos > 0); 1340 for (i = 1; i < NPAREN; i++) { 1341 if (p->pbegin[i] >= pos) { 1342 p->pbegin[i]++; 1343 } 1344 if (p->pend[i] >= pos) { 1345 p->pend[i]++; 1346 } 1347 } 1348 1349 memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos], 1350 (HERE()-pos-1)*sizeof(sop)); 1351 p->strip[pos] = s; 1352} 1353 1354/* 1355 - dofwd - complete a forward reference 1356 */ 1357static void 1358dofwd(struct parse *p, sopno pos, sop value) 1359{ 1360 /* avoid making error situations worse */ 1361 if (p->error != 0) 1362 return; 1363 1364 assert(value < 1<<OPSHIFT); 1365 p->strip[pos] = OP(p->strip[pos]) | value; 1366} 1367 1368/* 1369 - enlarge - enlarge the strip 1370 */ 1371static void 1372enlarge(struct parse *p, sopno size) 1373{ 1374 sop *sp; 1375 1376 if (p->ssize >= size) 1377 return; 1378 1379 sp = (sop *)realloc(p->strip, size*sizeof(sop)); 1380 if (sp == NULL) { 1381 SETERROR(REG_ESPACE); 1382 return; 1383 } 1384 p->strip = sp; 1385 p->ssize = size; 1386} 1387 1388/* 1389 - stripsnug - compact the strip 1390 */ 1391static void 1392stripsnug(struct parse *p, struct re_guts *g) 1393{ 1394 g->nstates = p->slen; 1395 g->strip = (sop *)realloc((char *)p->strip, p->slen * sizeof(sop)); 1396 if (g->strip == NULL) { 1397 SETERROR(REG_ESPACE); 1398 g->strip = p->strip; 1399 } 1400} 1401 1402/* 1403 - findmust - fill in must and mlen with longest mandatory literal string 1404 * 1405 * This algorithm could do fancy things like analyzing the operands of | 1406 * for common subsequences. Someday. This code is simple and finds most 1407 * of the interesting cases. 1408 * 1409 * Note that must and mlen got initialized during setup. 1410 */ 1411static void 1412findmust(struct parse *p, struct re_guts *g) 1413{ 1414 sop *scan; 1415 sop *start = NULL; /* start initialized in the default case, after that */ 1416 sop *newstart = NULL; /* newstart was initialized in the OCHAR case */ 1417 sopno newlen; 1418 sop s; 1419 char *cp; 1420 sopno i; 1421 1422 /* avoid making error situations worse */ 1423 if (p->error != 0) 1424 return; 1425 1426 /* find the longest OCHAR sequence in strip */ 1427 newlen = 0; 1428 scan = g->strip + 1; 1429 do { 1430 s = *scan++; 1431 switch (OP(s)) { 1432 case OCHAR: /* sequence member */ 1433 if (newlen == 0) /* new sequence */ 1434 newstart = scan - 1; 1435 newlen++; 1436 break; 1437 case OPLUS_: /* things that don't break one */ 1438 case OLPAREN: 1439 case ORPAREN: 1440 break; 1441 case OQUEST_: /* things that must be skipped */ 1442 case OCH_: 1443 scan--; 1444 do { 1445 scan += OPND(s); 1446 s = *scan; 1447 /* assert() interferes w debug printouts */ 1448 if (OP(s) != O_QUEST && OP(s) != O_CH && 1449 OP(s) != OOR2) { 1450 g->iflags |= BAD; 1451 return; 1452 } 1453 } while (OP(s) != O_QUEST && OP(s) != O_CH); 1454 /* fallthrough */ 1455 default: /* things that break a sequence */ 1456 if (newlen > g->mlen) { /* ends one */ 1457 start = newstart; 1458 g->mlen = newlen; 1459 } 1460 newlen = 0; 1461 break; 1462 } 1463 } while (OP(s) != OEND); 1464 1465 if (g->mlen == 0) /* there isn't one */ 1466 return; 1467 1468 /* turn it into a character string */ 1469 g->must = (char*)malloc((size_t)g->mlen + 1); 1470 if (g->must == NULL) { /* argh; just forget it */ 1471 g->mlen = 0; 1472 return; 1473 } 1474 cp = g->must; 1475 scan = start; 1476 for (i = g->mlen; i > 0; i--) { 1477 while (OP(s = *scan++) != OCHAR) 1478 continue; 1479 assert(cp < g->must + g->mlen); 1480 *cp++ = (char)OPND(s); 1481 } 1482 assert(cp == g->must + g->mlen); 1483 *cp++ = '\0'; /* just on general principles */ 1484} 1485 1486/* 1487 - pluscount - count + nesting 1488 */ 1489static sopno /* nesting depth */ 1490pluscount(struct parse *p, struct re_guts *g) 1491{ 1492 sop *scan; 1493 sop s; 1494 sopno plusnest = 0; 1495 sopno maxnest = 0; 1496 1497 if (p->error != 0) 1498 return(0); /* there may not be an OEND */ 1499 1500 scan = g->strip + 1; 1501 do { 1502 s = *scan++; 1503 switch (OP(s)) { 1504 case OPLUS_: 1505 plusnest++; 1506 break; 1507 case O_PLUS: 1508 if (plusnest > maxnest) 1509 maxnest = plusnest; 1510 plusnest--; 1511 break; 1512 } 1513 } while (OP(s) != OEND); 1514 if (plusnest != 0) 1515 g->iflags |= BAD; 1516 return(maxnest); 1517} 1518