Print this page
8993 sync regcomp(3C) with upstream


  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36 
  37 #include "lint.h"
  38 #include "file64.h"
  39 #include <sys/types.h>
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <ctype.h>
  43 #include <limits.h>
  44 #include <stdlib.h>
  45 #include <regex.h>


  46 #include <wchar.h>
  47 #include <wctype.h>
  48 
  49 #include "../locale/runetype.h"
  50 #include "../locale/collate.h"
  51 
  52 #include "utils.h"
  53 #include "regex2.h"
  54 
  55 #include "cname.h"
  56 #include "../locale/mblocal.h"
  57 
  58 /*


















  59  * parse structure, passed up and down to avoid global variables and
  60  * other clumsinesses
  61  */
  62 struct parse {
  63         const char *next;       /* next character in RE */
  64         const char *end;        /* end of string (-> NUL normally) */
  65         int error;              /* has an error been seen? */
  66         sop *strip;             /* malloced strip */
  67         sopno ssize;            /* malloced strip size (allocated) */
  68         sopno slen;             /* malloced strip length (used) */
  69         int ncsalloc;           /* number of csets allocated */
  70         struct re_guts *g;
  71 #define NPAREN  10              /* we need to remember () 1-9 for back refs */
  72         sopno pbegin[NPAREN];   /* -> ( ([0] unused) */
  73         sopno pend[NPAREN];     /* -> ) ([0] unused) */





  74 };
  75 
  76 /* ========= begin header generated by ./mkh ========= */
  77 #ifdef __cplusplus
  78 extern "C" {
  79 #endif
  80 
  81 /* === regcomp.c === */
  82 static void p_ere(struct parse *p, int stop);
  83 static void p_ere_exp(struct parse *p);
  84 static void p_str(struct parse *p);
  85 static void p_bre(struct parse *p, int end1, int end2);
  86 static int p_simp_re(struct parse *p, int starordinary);







  87 static int p_count(struct parse *p);
  88 static void p_bracket(struct parse *p);
  89 static void p_b_term(struct parse *p, cset *cs);
  90 static void p_b_cclass(struct parse *p, cset *cs);
  91 static void p_b_eclass(struct parse *p, cset *cs);
  92 static wint_t p_b_symbol(struct parse *p);
  93 static wint_t p_b_coll_elem(struct parse *p, wint_t endc);
  94 static wint_t othercase(wint_t ch);
  95 static void bothcases(struct parse *p, wint_t ch);
  96 static void ordinary(struct parse *p, wint_t ch);
  97 static void nonnewline(struct parse *p);
  98 static void repeat(struct parse *p, sopno start, int from, int to);
  99 static int seterr(struct parse *p, int e);
 100 static cset *allocset(struct parse *p);
 101 static void freeset(struct parse *p, cset *cs);
 102 static void CHadd(struct parse *p, cset *cs, wint_t ch);
 103 static void CHaddrange(struct parse *p, cset *cs, wint_t min, wint_t max);
 104 static void CHaddtype(struct parse *p, cset *cs, wctype_t wct);
 105 static wint_t singleton(cset *cs);
 106 static sopno dupl(struct parse *p, sopno start, sopno finish);


 116 static sopno pluscount(struct parse *p, struct re_guts *g);
 117 static wint_t wgetnext(struct parse *p);
 118 
 119 #ifdef __cplusplus
 120 }
 121 #endif
 122 /* ========= end header generated by ./mkh ========= */
 123 
 124 static char nuls[10];           /* place to point scanner in event of error */
 125 
 126 /*
 127  * macros for use with parse structure
 128  * BEWARE:  these know that the parse structure is named `p' !!!
 129  */
 130 #define PEEK()  (*p->next)
 131 #define PEEK2() (*(p->next+1))
 132 #define MORE()  (p->next < p->end)
 133 #define MORE2() (p->next+1 < p->end)
 134 #define SEE(c)  (MORE() && PEEK() == (c))
 135 #define SEETWO(a, b)    (MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))

 136 #define EAT(c)  ((SEE(c)) ? (NEXT(), 1) : 0)
 137 #define EATTWO(a, b)    ((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
 138 #define NEXT()  (p->next++)
 139 #define NEXT2() (p->next += 2)
 140 #define NEXTn(n)        (p->next += (n))
 141 #define GETNEXT()       (*p->next++)
 142 #define WGETNEXT()      wgetnext(p)
 143 #define SETERROR(e)     ((void)seterr(p, (e)))
 144 #define REQUIRE(co, e)  ((co) || seterr(p, e))
 145 #define MUSTSEE(c, e)   (REQUIRE(MORE() && PEEK() == (c), e))
 146 #define MUSTEAT(c, e)   (REQUIRE(MORE() && GETNEXT() == (c), e))
 147 #define MUSTNOTSEE(c, e)        (REQUIRE(!MORE() || PEEK() != (c), e))
 148 #define EMIT(op, sopnd) doemit(p, (sop)(op), (size_t)(sopnd))
 149 #define INSERT(op, pos) doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
 150 #define AHEAD(pos)              dofwd(p, pos, HERE()-(pos))
 151 #define ASTERN(sop, pos)        EMIT(sop, HERE()-pos)
 152 #define HERE()          (p->slen)
 153 #define THERE()         (p->slen - 1)
 154 #define THERETHERE()    (p->slen - 2)
 155 #define DROP(n) (p->slen -= (n))


 212         p->ssize = len/(size_t)2*(size_t)3 + (size_t)1;      /* ugh */
 213         assert(p->ssize >= len);
 214 
 215         p->strip = (sop *)malloc(p->ssize * sizeof (sop));
 216         p->slen = 0;
 217         if (p->strip == NULL) {
 218                 free((char *)g);
 219                 return (REG_ESPACE);
 220         }
 221 
 222         /* set things up */
 223         p->g = g;
 224         p->next = pattern;   /* convenience; we do not modify it */
 225         p->end = p->next + len;
 226         p->error = 0;
 227         p->ncsalloc = 0;
 228         for (i = 0; i < NPAREN; i++) {
 229                 p->pbegin[i] = 0;
 230                 p->pend[i] = 0;
 231         }













 232         g->sets = NULL;
 233         g->ncsets = 0;
 234         g->cflags = cflags;
 235         g->iflags = 0;
 236         g->nbol = 0;
 237         g->neol = 0;
 238         g->must = NULL;
 239         g->moffset = -1;
 240         g->charjump = NULL;
 241         g->matchjump = NULL;
 242         g->mlen = 0;
 243         g->nsub = 0;
 244         g->backrefs = 0;
 245 
 246         /* do it */
 247         EMIT(OEND, 0);
 248         g->firststate = THERE();
 249         if (cflags&REG_EXTENDED)
 250                 p_ere(p, OUT);
 251         else if (cflags&REG_NOSPEC)
 252                 p_str(p);
 253         else
 254                 p_bre(p, OUT, OUT);
 255         EMIT(OEND, 0);
 256         g->laststate = THERE();
 257 
 258         /* tidy up loose ends and fill things in */
 259         stripsnug(p, g);
 260         findmust(p, g);
 261         /*
 262          * only use Boyer-Moore algorithm if the pattern is bigger
 263          * than three characters
 264          */
 265         if (g->mlen > 3) {
 266                 computejumps(p, g);
 267                 computematchjumps(p, g);
 268                 if (g->matchjump == NULL && g->charjump != NULL) {
 269                         free(g->charjump);
 270                         g->charjump = NULL;
 271                 }
 272         }
 273         g->nplus = pluscount(p, g);
 274         g->magic = MAGIC2;
 275         preg->re_nsub = g->nsub;
 276         preg->re_g = g;
 277         preg->re_magic = MAGIC1;
 278 #ifndef REDEBUG
 279         /* not debugging, so can't rely on the assert() in regexec() */
 280         if (g->iflags&BAD)
 281                 SETERROR(REG_EFATAL);
 282 #endif
 283 
 284         /* win or lose, we're done */
 285         if (p->error != 0)   /* lose */
 286                 regfree(preg);
 287         return (p->error);
 288 }
 289 
 290 /*
 291  * p_ere - ERE parser top level, concatenation and alternation

 292  */
 293 static void
 294 p_ere(struct parse *p,
 295     int stop)           /* character this ERE should end at */
 296 {
 297         char c;
 298         sopno prevback;
 299         sopno prevfwd;
 300         sopno conc;
 301         int first = 1;          /* is this the first alternative? */
 302 
 303         for (;;) {
 304                 /* do a bunch of concatenated expressions */
 305                 conc = HERE();
 306                 while (MORE() && (c = PEEK()) != '|' && c != stop)
 307                         p_ere_exp(p);
 308                 /* require nonempty */
 309                 (void) REQUIRE(HERE() != conc, REG_BADPAT);
 310 
 311                 if (!EAT('|'))
 312                         break;          /* NOTE BREAK OUT */
 313 
 314                 if (first) {
 315                         INSERT(OCH_, conc);     /* offset is wrong */
 316                         prevfwd = conc;
 317                         prevback = conc;
 318                         first = 0;
 319                 }
 320                 ASTERN(OOR1, prevback);
 321                 prevback = THERE();
 322                 AHEAD(prevfwd);                 /* fix previous offset */
 323                 prevfwd = HERE();
 324                 EMIT(OOR2, 0);                  /* offset is very wrong */
 325         }
 326 
 327         if (!first) {           /* tail-end fixups */
 328                 AHEAD(prevfwd);
 329                 ASTERN(O_CH, prevback);
 330         }
 331 
 332         assert(!MORE() || SEE(stop));
 333 }
 334 
 335 /*
 336  * p_ere_exp - parse one subERE, an atom possibly followed by a repetition op
 337  */
 338 static void
 339 p_ere_exp(struct parse *p)
 340 {
 341         char c;
 342         wint_t wc;
 343         sopno pos;
 344         int count;
 345         int count2;
 346         sopno subno;
 347         int wascaret = 0;
 348 

 349         assert(MORE());         /* caller should have ensured this */
 350         c = GETNEXT();
 351 
 352         pos = HERE();
 353         switch (c) {
 354         case '(':
 355                 (void) REQUIRE(MORE(), REG_EPAREN);
 356                 p->g->nsub++;
 357                 subno = p->g->nsub;
 358                 if (subno < NPAREN)
 359                         p->pbegin[subno] = HERE();
 360                 EMIT(OLPAREN, subno);
 361                 if (!SEE(')'))
 362                         p_ere(p, ')');
 363                 if (subno < NPAREN) {
 364                         p->pend[subno] = HERE();
 365                         assert(p->pend[subno] != 0);
 366                 }
 367                 EMIT(ORPAREN, subno);
 368                 (void) MUSTEAT(')', REG_EPAREN);
 369                 break;
 370 #ifndef POSIX_MISTAKE
 371         case ')':               /* happens only if no current unmatched ( */
 372                 /*
 373                  * You may ask, why the ifndef?  Because I didn't notice
 374                  * this until slightly too late for 1003.2, and none of the
 375                  * other 1003.2 regular-expression reviewers noticed it at
 376                  * all.  So an unmatched ) is legal POSIX, at least until
 377                  * we can get it fixed.
 378                  */
 379                 SETERROR(REG_EPAREN);
 380                 break;
 381 #endif
 382         case '^':


 408         case '[':
 409                 p_bracket(p);
 410                 break;
 411         case '\\':
 412                 (void) REQUIRE(MORE(), REG_EESCAPE);
 413                 wc = WGETNEXT();
 414                 switch (wc) {
 415                 case '<':
 416                         EMIT(OBOW, 0);
 417                         break;
 418                 case '>':
 419                         EMIT(OEOW, 0);
 420                         break;
 421                 default:
 422                         ordinary(p, wc);
 423                         break;
 424                 }
 425                 break;
 426         default:
 427                 if (p->error != 0)
 428                         return;
 429                 p->next--;
 430                 wc = WGETNEXT();
 431                 ordinary(p, wc);
 432                 break;
 433         }
 434 
 435         if (!MORE())
 436                 return;
 437         c = PEEK();
 438         /* we call { a repetition if followed by a digit */
 439         if (!(c == '*' || c == '+' || c == '?' || c == '{'))
 440                 return;         /* no repetition, we're done */
 441         else if (c == '{')
 442                 (void) REQUIRE(MORE2() && \
 443                     (isdigit((uch)PEEK2()) || PEEK2() == ','), REG_BADRPT);
 444         NEXT();
 445 
 446         (void) REQUIRE(!wascaret, REG_BADRPT);
 447         switch (c) {
 448         case '*':       /* implemented as +? */
 449                 /* this case does not require the (y|) trick, noKLUDGE */
 450                 INSERT(OPLUS_, pos);
 451                 ASTERN(O_PLUS, pos);
 452                 INSERT(OQUEST_, pos);
 453                 ASTERN(O_QUEST, pos);
 454                 break;
 455         case '+':
 456                 INSERT(OPLUS_, pos);
 457                 ASTERN(O_PLUS, pos);
 458                 break;
 459         case '?':
 460                 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */


 469                 count = p_count(p);
 470                 if (EAT(',')) {
 471                         if (isdigit((uch)PEEK())) {
 472                                 count2 = p_count(p);
 473                                 (void) REQUIRE(count <= count2, REG_BADBR);
 474                         } else          /* single number with comma */
 475                                 count2 = INFINITY;
 476                 } else          /* just a single number */
 477                         count2 = count;
 478                 repeat(p, pos, count, count2);
 479                 if (!EAT('}')) {        /* error heuristics */
 480                         while (MORE() && PEEK() != '}')
 481                                 NEXT();
 482                         (void) REQUIRE(MORE(), REG_EBRACE);
 483                         SETERROR(REG_BADBR);
 484                 }
 485                 break;
 486         }
 487 
 488         if (!MORE())
 489                 return;
 490         c = PEEK();
 491         if (!(c == '*' || c == '+' || c == '?' ||
 492             (c == '{' && MORE2() && isdigit((uch)PEEK2()))))
 493                 return;
 494         SETERROR(REG_BADRPT);

 495 }
 496 
 497 /*
 498  * p_str - string (no metacharacters) "parser"
 499  */
 500 static void
 501 p_str(struct parse *p)
 502 {
 503         (void) REQUIRE(MORE(), REG_BADPAT);
 504         while (MORE())
 505                 ordinary(p, WGETNEXT());
 506 }
 507 
 508 /*
 509  * p_bre - BRE parser top level, anchoring and concatenation
 510  * Giving end1 as OUT essentially eliminates the end1/end2 check.
 511  *
 512  * This implementation is a bit of a kludge, in that a trailing $ is first
 513  * taken as an ordinary character and then revised to be an anchor.
 514  * The amount of lookahead needed to avoid this kludge is excessive.
 515  */
















 516 static void
 517 p_bre(struct parse *p,
 518     int end1,           /* first terminating character */
 519     int end2)           /* second terminating character */
 520 {
 521         sopno start = HERE();
 522         int first = 1;                  /* first subexpression? */
 523         int wasdollar = 0;


 524 






































































 525         if (EAT('^')) {
 526                 EMIT(OBOL, 0);
 527                 p->g->iflags |= USEBOL;
 528                 p->g->nbol++;
 529         }
 530         while (MORE() && !SEETWO(end1, end2)) {
 531                 wasdollar = p_simp_re(p, first);
 532                 first = 0;
 533         }
 534         if (wasdollar) {        /* oops, that was a trailing anchor */


 535                 DROP(1);
 536                 EMIT(OEOL, 0);
 537                 p->g->iflags |= USEEOL;
 538                 p->g->neol++;
 539         }

 540 
 541         (void) REQUIRE(HERE() != start, REG_BADPAT);    /* require nonempty */


















































 542 }
 543 
 544 /*
 545  * p_simp_re - parse a simple RE, an atom possibly followed by a repetition
 546  */
 547 static int                      /* was the simple RE an unbackslashed $? */
 548 p_simp_re(struct parse *p,
 549     int starordinary)   /* is a leading * an ordinary character? */
 550 {
 551         int c;
 552         int count;
 553         int count2;
 554         sopno pos;
 555         int i;
 556         wint_t wc;
 557         sopno subno;
 558 #define BACKSL  (1<<CHAR_BIT)
 559 
 560         pos = HERE();           /* repetition op, if any, covers from here */
 561 
 562         assert(MORE());         /* caller should have ensured this */
 563         c = GETNEXT();
 564         if (c == '\\') {
 565                 (void) REQUIRE(MORE(), REG_EESCAPE);
 566                 c = BACKSL | GETNEXT();
 567         }
 568         switch (c) {
 569         case '.':


 575         case '[':
 576                 p_bracket(p);
 577                 break;
 578         case BACKSL|'<':
 579                 EMIT(OBOW, 0);
 580                 break;
 581         case BACKSL|'>':
 582                 EMIT(OEOW, 0);
 583                 break;
 584         case BACKSL|'{':
 585                 SETERROR(REG_BADRPT);
 586                 break;
 587         case BACKSL|'(':
 588                 p->g->nsub++;
 589                 subno = p->g->nsub;
 590                 if (subno < NPAREN)
 591                         p->pbegin[subno] = HERE();
 592                 EMIT(OLPAREN, subno);
 593                 /* the MORE here is an error heuristic */
 594                 if (MORE() && !SEETWO('\\', ')'))
 595                         p_bre(p, '\\', ')');
 596                 if (subno < NPAREN) {
 597                         p->pend[subno] = HERE();
 598                         assert(p->pend[subno] != 0);
 599                 }
 600                 EMIT(ORPAREN, subno);
 601                 (void) REQUIRE(EATTWO('\\', ')'), REG_EPAREN);
 602                 break;
 603         case BACKSL|')':        /* should not get here -- must be user */
 604                 SETERROR(REG_EPAREN);
 605                 break;
 606         case BACKSL|'1':
 607         case BACKSL|'2':
 608         case BACKSL|'3':
 609         case BACKSL|'4':
 610         case BACKSL|'5':
 611         case BACKSL|'6':
 612         case BACKSL|'7':
 613         case BACKSL|'8':
 614         case BACKSL|'9':
 615                 i = (c&~BACKSL) - '0';
 616                 assert(i < NPAREN);
 617                 if (p->pend[i] != 0) {
 618                         assert(i <= p->g->nsub);
 619                         EMIT(OBACK_, i);
 620                         assert(p->pbegin[i] != 0);
 621                         assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
 622                         assert(OP(p->strip[p->pend[i]]) == ORPAREN);
 623                         (void) dupl(p, p->pbegin[i]+1, p->pend[i]);
 624                         EMIT(O_BACK, i);
 625                 } else
 626                         SETERROR(REG_ESUBREG);
 627                 p->g->backrefs = 1;
 628                 break;
 629         case '*':
 630                 (void) REQUIRE(starordinary, REG_BADRPT);





 631                 /* FALLTHROUGH */
 632         default:
 633                 if (p->error != 0)
 634                         return (0);     /* Definitely not $... */
 635                 p->next--;
 636                 wc = WGETNEXT();
 637                 ordinary(p, wc);
 638                 break;
 639         }
 640 
 641         if (EAT('*')) {         /* implemented as +? */
 642                 /* this case does not require the (y|) trick, noKLUDGE */
 643                 INSERT(OPLUS_, pos);
 644                 ASTERN(O_PLUS, pos);
 645                 INSERT(OQUEST_, pos);
 646                 ASTERN(O_QUEST, pos);
 647         } else if (EATTWO('\\', '{')) {
 648                 count = p_count(p);
 649                 if (EAT(',')) {
 650                         if (MORE() && isdigit((uch)PEEK())) {
 651                                 count2 = p_count(p);
 652                                 (void) REQUIRE(count <= count2, REG_BADBR);
 653                         } else          /* single number with comma */
 654                                 count2 = INFINITY;
 655                 } else          /* just a single number */
 656                         count2 = count;
 657                 repeat(p, pos, count, count2);
 658                 if (!EATTWO('\\', '}')) {       /* error heuristics */
 659                         while (MORE() && !SEETWO('\\', '}'))
 660                                 NEXT();
 661                         (void) REQUIRE(MORE(), REG_EBRACE);
 662                         SETERROR(REG_BADBR);
 663                 }
 664         } else if (c == '$')    /* $ (but not \$) ends it */
 665                 return (1);
 666 
 667         return (0);
 668 }
 669 
 670 /*
 671  * p_count - parse a repetition count
 672  */
 673 static int                      /* the value */
 674 p_count(struct parse *p)
 675 {
 676         int count = 0;
 677         int ndigits = 0;
 678 
 679         while (MORE() && isdigit((uch)PEEK()) && count <= DUPMAX) {
 680                 count = count*10 + (GETNEXT() - '0');
 681                 ndigits++;
 682         }
 683 
 684         (void) REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
 685         return (count);
 686 }
 687 


 876  * p_b_coll_elem - parse a collating-element name and look it up
 877  */
 878 static wint_t                   /* value of collating element */
 879 p_b_coll_elem(struct parse *p,
 880     wint_t endc)                /* name ended by endc,']' */
 881 {
 882         const char *sp = p->next;
 883         struct cname *cp;
 884         mbstate_t mbs;
 885         wchar_t wc;
 886         size_t clen, len;
 887 
 888         while (MORE() && !SEETWO(endc, ']'))
 889                 NEXT();
 890         if (!MORE()) {
 891                 SETERROR(REG_EBRACK);
 892                 return (0);
 893         }
 894         len = p->next - sp;
 895         for (cp = cnames; cp->name != NULL; cp++)
 896                 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
 897                         return (cp->code);   /* known name */
 898         (void) memset(&mbs, 0, sizeof (mbs));
 899         if ((clen = mbrtowc(&wc, sp, len, &mbs)) == len)
 900                 return (wc);                    /* single character */
 901         else if (clen == (size_t)-1 || clen == (size_t)-2)
 902                 SETERROR(REG_ECHAR);
 903         else
 904                 SETERROR(REG_ECOLLATE);         /* neither */
 905         return (0);
 906 }
 907 
 908 /*
 909  * othercase - return the case counterpart of an alphabetic
 910  */
 911 static wint_t                   /* if no counterpart, return ch */
 912 othercase(wint_t ch)
 913 {
 914         assert(iswalpha(ch));
 915         if (iswupper(ch))
 916                 return (towlower(ch));


1419                                 (void) memset(&mbs, 0, sizeof (mbs));
1420                                 newstart = scan - 1;
1421                         }
1422                         clen = wcrtomb(buf, OPND(s), &mbs);
1423                         if (clen == (size_t)-1)
1424                                 goto toohard;
1425                         newlen += clen;
1426                         break;
1427                 case OPLUS_:            /* things that don't break one */
1428                 case OLPAREN:
1429                 case ORPAREN:
1430                         break;
1431                 case OQUEST_:           /* things that must be skipped */
1432                 case OCH_:
1433                         offset = altoffset(scan, offset);
1434                         scan--;
1435                         do {
1436                                 scan += OPND(s);
1437                                 s = *scan;
1438                                 /* assert() interferes w debug printouts */
1439                                 if (OP(s) != O_QUEST && OP(s) != O_CH &&
1440                                     OP(s) != OOR2) {
1441                                         g->iflags |= BAD;
1442                                         return;
1443                                 }
1444                         } while (OP(s) != O_QUEST && OP(s) != O_CH);
1445                         /* FALLTHROUGH */
1446                 case OBOW:              /* things that break a sequence */
1447                 case OEOW:
1448                 case OBOL:
1449                 case OEOL:
1450                 case O_QUEST:
1451                 case O_CH:
1452                 case OEND:
1453                         if (newlen > g->mlen) {           /* ends one */
1454                                 start = newstart;
1455                                 g->mlen = newlen;
1456                                 if (offset > -1) {
1457                                         g->moffset += offset;
1458                                         offset = newlen;
1459                                 } else
1460                                         g->moffset = offset;
1461                         } else {
1462                                 if (offset > -1)
1463                                         offset += newlen;
1464                         }
1465                         newlen = 0;
1466                         break;
1467                 case OANY:
1468                         if (newlen > g->mlen) {           /* ends one */
1469                                 start = newstart;
1470                                 g->mlen = newlen;
1471                                 if (offset > -1) {
1472                                         g->moffset += offset;
1473                                         offset = newlen;
1474                                 } else
1475                                         g->moffset = offset;
1476                         } else {
1477                                 if (offset > -1)
1478                                         offset += newlen;
1479                         }
1480                         if (offset > -1)
1481                                 offset++;
1482                         newlen = 0;
1483                         break;
1484                 case OANYOF:            /* may or may not invalidate offset */
1485                         /* First, everything as OANY */
1486                         if (newlen > g->mlen) {           /* ends one */
1487                                 start = newstart;
1488                                 g->mlen = newlen;
1489                                 if (offset > -1) {
1490                                         g->moffset += offset;
1491                                         offset = newlen;
1492                                 } else
1493                                         g->moffset = offset;
1494                         } else {
1495                                 if (offset > -1)
1496                                         offset += newlen;
1497                         }
1498                         if (offset > -1)
1499                                 offset++;
1500                         newlen = 0;
1501                         break;
1502                 toohard:
1503                 default:
1504                         /*
1505                          * Anything here makes it impossible or too hard
1506                          * to calculate the offset -- so we give up;
1507                          * save the last known good offset, in case the
1508                          * must sequence doesn't occur later.
1509                          */
1510                         if (newlen > g->mlen) {           /* ends one */
1511                                 start = newstart;
1512                                 g->mlen = newlen;
1513                                 if (offset > -1)
1514                                         g->moffset += offset;
1515                                 else
1516                                         g->moffset = offset;
1517                         }
1518                         offset = -1;
1519                         newlen = 0;
1520                         break;
1521                 }
1522         } while (OP(s) != OEND);
1523 
1524         if (g->mlen == 0) {          /* there isn't one */
1525                 g->moffset = -1;
1526                 return;
1527         }
1528 
1529         /* turn it into a character string */
1530         g->must = malloc((size_t)g->mlen + 1);


1550 /*
1551  * altoffset - choose biggest offset among multiple choices
1552  *
1553  * Compute, recursively if necessary, the largest offset among multiple
1554  * re paths.
1555  */
1556 static int
1557 altoffset(sop *scan, int offset)
1558 {
1559         int largest;
1560         int try;
1561         sop s;
1562 
1563         /* If we gave up already on offsets, return */
1564         if (offset == -1)
1565                 return (-1);
1566 
1567         largest = 0;
1568         try = 0;
1569         s = *scan++;
1570         while (OP(s) != O_QUEST && OP(s) != O_CH) {
1571                 switch (OP(s)) {
1572                 case OOR1:
1573                         if (try > largest)
1574                                 largest = try;
1575                         try = 0;
1576                         break;
1577                 case OQUEST_:
1578                 case OCH_:
1579                         try = altoffset(scan, try);
1580                         if (try == -1)
1581                                 return (-1);
1582                         scan--;
1583                         do {
1584                                 scan += OPND(s);
1585                                 s = *scan;
1586                                 if (OP(s) != O_QUEST && OP(s) != O_CH &&
1587                                     OP(s) != OOR2)
1588                                         return (-1);
1589                         } while (OP(s) != O_QUEST && OP(s) != O_CH);
1590                         /*
1591                          * We must skip to the next position, or we'll
1592                          * leave altoffset() too early.
1593                          */
1594                         scan++;
1595                         break;
1596                 case OANYOF:
1597                 case OCHAR:
1598                 case OANY:
1599                         try++;
1600                         /*FALLTHRU*/
1601                 case OBOW:
1602                 case OEOW:
1603                 case OLPAREN:
1604                 case ORPAREN:
1605                 case OOR2:
1606                         break;
1607                 default:
1608                         try = -1;
1609                         break;




  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36 
  37 #include "lint.h"
  38 #include "file64.h"
  39 #include <sys/types.h>
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <ctype.h>
  43 #include <limits.h>

  44 #include <regex.h>
  45 #include <stdlib.h>
  46 #include <stdbool.h>
  47 #include <wchar.h>
  48 #include <wctype.h>
  49 
  50 #include "../locale/runetype.h"
  51 #include "../locale/collate.h"
  52 
  53 #include "utils.h"
  54 #include "regex2.h"
  55 
  56 #include "cname.h"
  57 #include "../locale/mblocal.h"
  58 
  59 /*
  60  * Branching context, used to keep track of branch state for all of the branch-
  61  * aware functions. In addition to keeping track of branch positions for the
  62  * p_branch_* functions, we use this to simplify some clumsiness in BREs for
  63  * detection of whether ^ is acting as an anchor or being used erroneously and
  64  * also for whether we're in a sub-expression or not.
  65  */
  66 struct branchc {
  67         sopno start;
  68         sopno back;
  69         sopno fwd;
  70 
  71         int nbranch;
  72         int nchain;
  73         bool outer;
  74         bool terminate;
  75 };
  76 
  77 /*
  78  * parse structure, passed up and down to avoid global variables and
  79  * other clumsinesses
  80  */
  81 struct parse {
  82         const char *next;       /* next character in RE */
  83         const char *end;        /* end of string (-> NUL normally) */
  84         int error;              /* has an error been seen? */
  85         sop *strip;             /* malloced strip */
  86         sopno ssize;            /* malloced strip size (allocated) */
  87         sopno slen;             /* malloced strip length (used) */
  88         int ncsalloc;           /* number of csets allocated */
  89         struct re_guts *g;
  90 #define NPAREN  10              /* we need to remember () 1-9 for back refs */
  91         sopno pbegin[NPAREN];   /* -> ( ([0] unused) */
  92         sopno pend[NPAREN];     /* -> ) ([0] unused) */
  93         bool allowbranch;       /* can this expression branch? */
  94         bool bre;               /* convenience; is this a BRE? */
  95         bool (*parse_expr)(struct parse *, struct branchc *);
  96         void (*pre_parse)(struct parse *, struct branchc *);
  97         void (*post_parse)(struct parse *, struct branchc *);
  98 };
  99 
 100 /* ========= begin header generated by ./mkh ========= */
 101 #ifdef __cplusplus
 102 extern "C" {
 103 #endif
 104 
 105 /* === regcomp.c === */
 106 static bool p_ere_exp(struct parse *p, struct branchc *bc);

 107 static void p_str(struct parse *p);
 108 static int p_branch_eat_delim(struct parse *p, struct branchc *bc);
 109 static void p_branch_ins_offset(struct parse *p, struct branchc *bc);
 110 static void p_branch_fix_tail(struct parse *p, struct branchc *bc);
 111 static bool p_branch_empty(struct parse *p, struct branchc *bc);
 112 static bool p_branch_do(struct parse *p, struct branchc *bc);
 113 static void p_bre_pre_parse(struct parse *p, struct branchc *bc);
 114 static void p_bre_post_parse(struct parse *p, struct branchc *bc);
 115 static void p_re(struct parse *p, int end1, int end2);
 116 static bool p_simp_re(struct parse *p, struct branchc *bc);
 117 static int p_count(struct parse *p);
 118 static void p_bracket(struct parse *p);
 119 static void p_b_term(struct parse *p, cset *cs);
 120 static void p_b_cclass(struct parse *p, cset *cs);
 121 static void p_b_eclass(struct parse *p, cset *cs);
 122 static wint_t p_b_symbol(struct parse *p);
 123 static wint_t p_b_coll_elem(struct parse *p, wint_t endc);
 124 static wint_t othercase(wint_t ch);
 125 static void bothcases(struct parse *p, wint_t ch);
 126 static void ordinary(struct parse *p, wint_t ch);
 127 static void nonnewline(struct parse *p);
 128 static void repeat(struct parse *p, sopno start, int from, int to);
 129 static int seterr(struct parse *p, int e);
 130 static cset *allocset(struct parse *p);
 131 static void freeset(struct parse *p, cset *cs);
 132 static void CHadd(struct parse *p, cset *cs, wint_t ch);
 133 static void CHaddrange(struct parse *p, cset *cs, wint_t min, wint_t max);
 134 static void CHaddtype(struct parse *p, cset *cs, wctype_t wct);
 135 static wint_t singleton(cset *cs);
 136 static sopno dupl(struct parse *p, sopno start, sopno finish);


 146 static sopno pluscount(struct parse *p, struct re_guts *g);
 147 static wint_t wgetnext(struct parse *p);
 148 
 149 #ifdef __cplusplus
 150 }
 151 #endif
 152 /* ========= end header generated by ./mkh ========= */
 153 
 154 static char nuls[10];           /* place to point scanner in event of error */
 155 
 156 /*
 157  * macros for use with parse structure
 158  * BEWARE:  these know that the parse structure is named `p' !!!
 159  */
 160 #define PEEK()  (*p->next)
 161 #define PEEK2() (*(p->next+1))
 162 #define MORE()  (p->next < p->end)
 163 #define MORE2() (p->next+1 < p->end)
 164 #define SEE(c)  (MORE() && PEEK() == (c))
 165 #define SEETWO(a, b)    (MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
 166 #define SEESPEC(a)      (p->bre ? SEETWO('\\', a) : SEE(a))
 167 #define EAT(c)  ((SEE(c)) ? (NEXT(), 1) : 0)
 168 #define EATTWO(a, b)    ((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
 169 #define NEXT()  (p->next++)
 170 #define NEXT2() (p->next += 2)
 171 #define NEXTn(n)        (p->next += (n))
 172 #define GETNEXT()       (*p->next++)
 173 #define WGETNEXT()      wgetnext(p)
 174 #define SETERROR(e)     ((void)seterr(p, (e)))
 175 #define REQUIRE(co, e)  ((co) || seterr(p, e))
 176 #define MUSTSEE(c, e)   (REQUIRE(MORE() && PEEK() == (c), e))
 177 #define MUSTEAT(c, e)   (REQUIRE(MORE() && GETNEXT() == (c), e))
 178 #define MUSTNOTSEE(c, e)        (REQUIRE(!MORE() || PEEK() != (c), e))
 179 #define EMIT(op, sopnd) doemit(p, (sop)(op), (size_t)(sopnd))
 180 #define INSERT(op, pos) doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
 181 #define AHEAD(pos)              dofwd(p, pos, HERE()-(pos))
 182 #define ASTERN(sop, pos)        EMIT(sop, HERE()-pos)
 183 #define HERE()          (p->slen)
 184 #define THERE()         (p->slen - 1)
 185 #define THERETHERE()    (p->slen - 2)
 186 #define DROP(n) (p->slen -= (n))


 243         p->ssize = len/(size_t)2*(size_t)3 + (size_t)1;      /* ugh */
 244         assert(p->ssize >= len);
 245 
 246         p->strip = (sop *)malloc(p->ssize * sizeof (sop));
 247         p->slen = 0;
 248         if (p->strip == NULL) {
 249                 free((char *)g);
 250                 return (REG_ESPACE);
 251         }
 252 
 253         /* set things up */
 254         p->g = g;
 255         p->next = pattern;   /* convenience; we do not modify it */
 256         p->end = p->next + len;
 257         p->error = 0;
 258         p->ncsalloc = 0;
 259         for (i = 0; i < NPAREN; i++) {
 260                 p->pbegin[i] = 0;
 261                 p->pend[i] = 0;
 262         }
 263         if (cflags & REG_EXTENDED) {
 264                 p->allowbranch = true;
 265                 p->bre = false;
 266                 p->parse_expr = p_ere_exp;
 267                 p->pre_parse = NULL;
 268                 p->post_parse = NULL;
 269         } else {
 270                 p->allowbranch = false;
 271                 p->bre = true;
 272                 p->parse_expr = p_simp_re;
 273                 p->pre_parse = p_bre_pre_parse;
 274                 p->post_parse = p_bre_post_parse;
 275         }
 276         g->sets = NULL;
 277         g->ncsets = 0;
 278         g->cflags = cflags;
 279         g->iflags = 0;
 280         g->nbol = 0;
 281         g->neol = 0;
 282         g->must = NULL;
 283         g->moffset = -1;
 284         g->charjump = NULL;
 285         g->matchjump = NULL;
 286         g->mlen = 0;
 287         g->nsub = 0;
 288         g->backrefs = 0;
 289 
 290         /* do it */
 291         EMIT(OEND, 0);
 292         g->firststate = THERE();
 293         if (cflags & REG_NOSPEC)


 294                 p_str(p);
 295         else
 296                 p_re(p, OUT, OUT);
 297         EMIT(OEND, 0);
 298         g->laststate = THERE();
 299 
 300         /* tidy up loose ends and fill things in */
 301         stripsnug(p, g);
 302         findmust(p, g);
 303         /*
 304          * only use Boyer-Moore algorithm if the pattern is bigger
 305          * than three characters
 306          */
 307         if (g->mlen > 3) {
 308                 computejumps(p, g);
 309                 computematchjumps(p, g);
 310                 if (g->matchjump == NULL && g->charjump != NULL) {
 311                         free(g->charjump);
 312                         g->charjump = NULL;
 313                 }
 314         }
 315         g->nplus = pluscount(p, g);
 316         g->magic = MAGIC2;
 317         preg->re_nsub = g->nsub;
 318         preg->re_g = g;
 319         preg->re_magic = MAGIC1;
 320 #ifndef REDEBUG
 321         /* not debugging, so can't rely on the assert() in regexec() */
 322         if (g->iflags&BAD)
 323                 SETERROR(REG_EFATAL);
 324 #endif
 325 
 326         /* win or lose, we're done */
 327         if (p->error != 0)   /* lose */
 328                 regfree(preg);
 329         return (p->error);
 330 }
 331 
 332 /*
 333  * Parse one subERE, an atom possibly followed by a repetition op,
 334  * return whether we should terminate or not.
 335  */
 336 static bool
 337 p_ere_exp(struct parse *p, struct branchc *bc)

 338 {
 339         char c;












































 340         wint_t wc;
 341         sopno pos;
 342         int count;
 343         int count2;
 344         sopno subno;
 345         int wascaret = 0;
 346 
 347         (void) bc;
 348         assert(MORE());         /* caller should have ensured this */
 349         c = GETNEXT();
 350 
 351         pos = HERE();
 352         switch (c) {
 353         case '(':
 354                 (void) REQUIRE(MORE(), REG_EPAREN);
 355                 p->g->nsub++;
 356                 subno = p->g->nsub;
 357                 if (subno < NPAREN)
 358                         p->pbegin[subno] = HERE();
 359                 EMIT(OLPAREN, subno);
 360                 if (!SEE(')'))
 361                         p_re(p, ')', IGN);
 362                 if (subno < NPAREN) {
 363                         p->pend[subno] = HERE();
 364                         assert(p->pend[subno] != 0);
 365                 }
 366                 EMIT(ORPAREN, subno);
 367                 (void) MUSTEAT(')', REG_EPAREN);
 368                 break;
 369 #ifndef POSIX_MISTAKE
 370         case ')':               /* happens only if no current unmatched ( */
 371                 /*
 372                  * You may ask, why the ifndef?  Because I didn't notice
 373                  * this until slightly too late for 1003.2, and none of the
 374                  * other 1003.2 regular-expression reviewers noticed it at
 375                  * all.  So an unmatched ) is legal POSIX, at least until
 376                  * we can get it fixed.
 377                  */
 378                 SETERROR(REG_EPAREN);
 379                 break;
 380 #endif
 381         case '^':


 407         case '[':
 408                 p_bracket(p);
 409                 break;
 410         case '\\':
 411                 (void) REQUIRE(MORE(), REG_EESCAPE);
 412                 wc = WGETNEXT();
 413                 switch (wc) {
 414                 case '<':
 415                         EMIT(OBOW, 0);
 416                         break;
 417                 case '>':
 418                         EMIT(OEOW, 0);
 419                         break;
 420                 default:
 421                         ordinary(p, wc);
 422                         break;
 423                 }
 424                 break;
 425         default:
 426                 if (p->error != 0)
 427                         return (false);
 428                 p->next--;
 429                 wc = WGETNEXT();
 430                 ordinary(p, wc);
 431                 break;
 432         }
 433 
 434         if (!MORE())
 435                 return (false);
 436         c = PEEK();
 437         /* we call { a repetition if followed by a digit */
 438         if (!(c == '*' || c == '+' || c == '?' || c == '{'))
 439                 return (false);         /* no repetition, we're done */
 440         else if (c == '{')
 441                 (void) REQUIRE(MORE2() && \
 442                     (isdigit((uch)PEEK2()) || PEEK2() == ','), REG_BADRPT);
 443         NEXT();
 444 
 445         (void) REQUIRE(!wascaret, REG_BADRPT);
 446         switch (c) {
 447         case '*':       /* implemented as +? */
 448                 /* this case does not require the (y|) trick, noKLUDGE */
 449                 INSERT(OPLUS_, pos);
 450                 ASTERN(O_PLUS, pos);
 451                 INSERT(OQUEST_, pos);
 452                 ASTERN(O_QUEST, pos);
 453                 break;
 454         case '+':
 455                 INSERT(OPLUS_, pos);
 456                 ASTERN(O_PLUS, pos);
 457                 break;
 458         case '?':
 459                 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */


 468                 count = p_count(p);
 469                 if (EAT(',')) {
 470                         if (isdigit((uch)PEEK())) {
 471                                 count2 = p_count(p);
 472                                 (void) REQUIRE(count <= count2, REG_BADBR);
 473                         } else          /* single number with comma */
 474                                 count2 = INFINITY;
 475                 } else          /* just a single number */
 476                         count2 = count;
 477                 repeat(p, pos, count, count2);
 478                 if (!EAT('}')) {        /* error heuristics */
 479                         while (MORE() && PEEK() != '}')
 480                                 NEXT();
 481                         (void) REQUIRE(MORE(), REG_EBRACE);
 482                         SETERROR(REG_BADBR);
 483                 }
 484                 break;
 485         }
 486 
 487         if (!MORE())
 488                 return (false);
 489         c = PEEK();
 490         if (!(c == '*' || c == '+' || c == '?' ||
 491             (c == '{' && MORE2() && isdigit((uch)PEEK2()))))
 492                 return (false);
 493         SETERROR(REG_BADRPT);
 494         return (false);
 495 }
 496 
 497 /*
 498  * p_str - string (no metacharacters) "parser"
 499  */
 500 static void
 501 p_str(struct parse *p)
 502 {
 503         (void) REQUIRE(MORE(), REG_BADPAT);
 504         while (MORE())
 505                 ordinary(p, WGETNEXT());
 506 }
 507 
 508 /*
 509  * Eat consecutive branch delimiters for the kind of expression that we are
 510  * parsing, return the number of delimiters that we ate.




 511  */
 512 static int
 513 p_branch_eat_delim(struct parse *p, struct branchc *bc)
 514 {
 515         int nskip;
 516 
 517         (void) bc;
 518         nskip = 0;
 519         while (EAT('|'))
 520                 ++nskip;
 521         return (nskip);
 522 }
 523 
 524 /*
 525  * Insert necessary branch book-keeping operations. This emits a
 526  * bogus 'next' offset, since we still have more to parse
 527  */
 528 static void
 529 p_branch_ins_offset(struct parse *p, struct branchc *bc)


 530 {
 531         if (bc->nbranch == 0) {
 532                 INSERT(OCH_, bc->start);     /* offset is wrong */
 533                 bc->fwd = bc->start;
 534                 bc->back = bc->start;
 535         }
 536 
 537         ASTERN(OOR1, bc->back);
 538         bc->back = THERE();
 539         AHEAD(bc->fwd);                      /* fix previous offset */
 540         bc->fwd = HERE();
 541         EMIT(OOR2, 0);                  /* offset is very wrong */
 542         ++bc->nbranch;
 543 }
 544 
 545 /*
 546  * Fix the offset of the tail branch, if we actually had any branches.
 547  * This is to correct the bogus placeholder offset that we use.
 548  */
 549 static void
 550 p_branch_fix_tail(struct parse *p, struct branchc *bc)
 551 {
 552         /* Fix bogus offset at the tail if we actually have branches */
 553         if (bc->nbranch > 0) {
 554                 AHEAD(bc->fwd);
 555                 ASTERN(O_CH, bc->back);
 556         }
 557 }
 558 
 559 /*
 560  * Signal to the parser that an empty branch has been encountered; this will,
 561  * in the future, be used to allow for more permissive behavior with empty
 562  * branches. The return value should indicate whether parsing may continue
 563  * or not.
 564  */
 565 static bool
 566 p_branch_empty(struct parse *p, struct branchc *bc)
 567 {
 568         (void) bc;
 569         SETERROR(REG_BADPAT);
 570         return (false);
 571 }
 572 
 573 /*
 574  * Take care of any branching requirements. This includes inserting the
 575  * appropriate branching instructions as well as eating all of the branch
 576  * delimiters until we either run out of pattern or need to parse more pattern.
 577  */
 578 static bool
 579 p_branch_do(struct parse *p, struct branchc *bc)
 580 {
 581         int ate = 0;
 582 
 583         ate = p_branch_eat_delim(p, bc);
 584         if (ate == 0)
 585                 return (false);
 586         else if ((ate > 1 || (bc->outer && !MORE())) && !p_branch_empty(p, bc))
 587                 /*
 588                  * Halt parsing only if we have an empty branch and
 589                  * p_branch_empty indicates that we must not continue.
 590                  * In the future, this will not  necessarily be an error.
 591                  */
 592                 return (false);
 593         p_branch_ins_offset(p, bc);
 594 
 595         return (true);
 596 }
 597 
 598 static void
 599 p_bre_pre_parse(struct parse *p, struct branchc *bc)
 600 {
 601         (void) bc;
 602         /*
 603          * Does not move cleanly into expression parser because of
 604          * ordinary interpration of * at the beginning position of
 605          * an expression.
 606          */
 607         if (EAT('^')) {
 608                 EMIT(OBOL, 0);
 609                 p->g->iflags |= USEBOL;
 610                 p->g->nbol++;
 611         }
 612 }
 613 
 614 static void
 615 p_bre_post_parse(struct parse *p, struct branchc *bc)
 616 {
 617         /* Expression is terminating due to EOL token */
 618         if (bc->terminate) {
 619                 DROP(1);
 620                 EMIT(OEOL, 0);
 621                 p->g->iflags |= USEEOL;
 622                 p->g->neol++;
 623         }
 624 }
 625 
 626 /*
 627  * Top level parser, concatenation and BRE anchoring.
 628  * Giving end1 as OUT essentially eliminates the end1/end2 check.
 629  *
 630  * This implementation is a bit of a kludge, in that a trailing $ is first
 631  * taken as an ordinary character and then revised to be an anchor.
 632  * The amount of lookahead needed to avoid this kludge is excessive.
 633  */
 634 static void
 635 p_re(struct parse *p,
 636     int end1,   /* first terminating character */
 637     int end2)   /* second terminating character; ignored for EREs */
 638 {
 639         struct branchc bc;
 640 
 641         bc.nbranch = 0;
 642         if (end1 == OUT && end2 == OUT)
 643                 bc.outer = true;
 644         else
 645                 bc.outer = false;
 646 #define SEEEND()        (!p->bre ? SEE(end1) : SEETWO(end1, end2))
 647         for (;;) {
 648                 bc.start = HERE();
 649                 bc.nchain = 0;
 650                 bc.terminate = false;
 651                 if (p->pre_parse != NULL)
 652                         p->pre_parse(p, &bc);
 653                 while (MORE() && (!p->allowbranch || !SEESPEC('|')) &&
 654                     !SEEEND()) {
 655                         bc.terminate = p->parse_expr(p, &bc);
 656                         ++bc.nchain;
 657                 }
 658                 if (p->post_parse != NULL)
 659                         p->post_parse(p, &bc);
 660                 (void) REQUIRE(HERE() != bc.start, REG_BADPAT);
 661                 if (!p->allowbranch)
 662                         break;
 663                 /*
 664                  * p_branch_do's return value indicates whether we should
 665                  * continue parsing or not. This is both for correctness and
 666                  * a slight optimization, because it will check if we've
 667                  * encountered an empty branch or the end of the string
 668                  * immediately following a branch delimiter.
 669                  */
 670                 if (!p_branch_do(p, &bc))
 671                         break;
 672         }
 673 #undef SEE_END
 674         if (p->allowbranch)
 675                 p_branch_fix_tail(p, &bc);
 676         assert(!MORE() || SEE(end1));
 677 }
 678 
 679 /*
 680  * p_simp_re - parse a simple RE, an atom possibly followed by a repetition
 681  */
 682 static bool                     /* was the simple RE an unbackslashed $? */
 683 p_simp_re(struct parse *p, struct branchc *bc)

 684 {
 685         int c;
 686         int count;
 687         int count2;
 688         sopno pos;
 689         int i;
 690         wint_t wc;
 691         sopno subno;
 692 #define BACKSL  (1<<CHAR_BIT)
 693 
 694         pos = HERE();           /* repetition op, if any, covers from here */
 695 
 696         assert(MORE());         /* caller should have ensured this */
 697         c = GETNEXT();
 698         if (c == '\\') {
 699                 (void) REQUIRE(MORE(), REG_EESCAPE);
 700                 c = BACKSL | GETNEXT();
 701         }
 702         switch (c) {
 703         case '.':


 709         case '[':
 710                 p_bracket(p);
 711                 break;
 712         case BACKSL|'<':
 713                 EMIT(OBOW, 0);
 714                 break;
 715         case BACKSL|'>':
 716                 EMIT(OEOW, 0);
 717                 break;
 718         case BACKSL|'{':
 719                 SETERROR(REG_BADRPT);
 720                 break;
 721         case BACKSL|'(':
 722                 p->g->nsub++;
 723                 subno = p->g->nsub;
 724                 if (subno < NPAREN)
 725                         p->pbegin[subno] = HERE();
 726                 EMIT(OLPAREN, subno);
 727                 /* the MORE here is an error heuristic */
 728                 if (MORE() && !SEETWO('\\', ')'))
 729                         p_re(p, '\\', ')');
 730                 if (subno < NPAREN) {
 731                         p->pend[subno] = HERE();
 732                         assert(p->pend[subno] != 0);
 733                 }
 734                 EMIT(ORPAREN, subno);
 735                 (void) REQUIRE(EATTWO('\\', ')'), REG_EPAREN);
 736                 break;
 737         case BACKSL|')':        /* should not get here -- must be user */
 738                 SETERROR(REG_EPAREN);
 739                 break;
 740         case BACKSL|'1':
 741         case BACKSL|'2':
 742         case BACKSL|'3':
 743         case BACKSL|'4':
 744         case BACKSL|'5':
 745         case BACKSL|'6':
 746         case BACKSL|'7':
 747         case BACKSL|'8':
 748         case BACKSL|'9':
 749                 i = (c&~BACKSL) - '0';
 750                 assert(i < NPAREN);
 751                 if (p->pend[i] != 0) {
 752                         assert(i <= p->g->nsub);
 753                         EMIT(OBACK_, i);
 754                         assert(p->pbegin[i] != 0);
 755                         assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
 756                         assert(OP(p->strip[p->pend[i]]) == ORPAREN);
 757                         (void) dupl(p, p->pbegin[i]+1, p->pend[i]);
 758                         EMIT(O_BACK, i);
 759                 } else
 760                         SETERROR(REG_ESUBREG);
 761                 p->g->backrefs = 1;
 762                 break;
 763         case '*':
 764                 /*
 765                  * Ordinary if used as the first character beyond BOL anchor of
 766                  * a (sub-)expression, counts as a bad repetition operator if it
 767                  * appears otherwise.
 768                  */
 769                 (void) REQUIRE(bc->nchain == 0, REG_BADRPT);
 770                 /* FALLTHROUGH */
 771         default:
 772                 if (p->error != 0)
 773                         return (false); /* Definitely not $... */
 774                 p->next--;
 775                 wc = WGETNEXT();
 776                 ordinary(p, wc);
 777                 break;
 778         }
 779 
 780         if (EAT('*')) {         /* implemented as +? */
 781                 /* this case does not require the (y|) trick, noKLUDGE */
 782                 INSERT(OPLUS_, pos);
 783                 ASTERN(O_PLUS, pos);
 784                 INSERT(OQUEST_, pos);
 785                 ASTERN(O_QUEST, pos);
 786         } else if (EATTWO('\\', '{')) {
 787                 count = p_count(p);
 788                 if (EAT(',')) {
 789                         if (MORE() && isdigit((uch)PEEK())) {
 790                                 count2 = p_count(p);
 791                                 (void) REQUIRE(count <= count2, REG_BADBR);
 792                         } else          /* single number with comma */
 793                                 count2 = INFINITY;
 794                 } else          /* just a single number */
 795                         count2 = count;
 796                 repeat(p, pos, count, count2);
 797                 if (!EATTWO('\\', '}')) {       /* error heuristics */
 798                         while (MORE() && !SEETWO('\\', '}'))
 799                                 NEXT();
 800                         (void) REQUIRE(MORE(), REG_EBRACE);
 801                         SETERROR(REG_BADBR);
 802                 }
 803         } else if (c == '$')    /* $ (but not \$) ends it */
 804                 return (true);
 805 
 806         return (false);
 807 }
 808 
 809 /*
 810  * p_count - parse a repetition count
 811  */
 812 static int                      /* the value */
 813 p_count(struct parse *p)
 814 {
 815         int count = 0;
 816         int ndigits = 0;
 817 
 818         while (MORE() && isdigit((uch)PEEK()) && count <= DUPMAX) {
 819                 count = count*10 + (GETNEXT() - '0');
 820                 ndigits++;
 821         }
 822 
 823         (void) REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
 824         return (count);
 825 }
 826 


1015  * p_b_coll_elem - parse a collating-element name and look it up
1016  */
1017 static wint_t                   /* value of collating element */
1018 p_b_coll_elem(struct parse *p,
1019     wint_t endc)                /* name ended by endc,']' */
1020 {
1021         const char *sp = p->next;
1022         struct cname *cp;
1023         mbstate_t mbs;
1024         wchar_t wc;
1025         size_t clen, len;
1026 
1027         while (MORE() && !SEETWO(endc, ']'))
1028                 NEXT();
1029         if (!MORE()) {
1030                 SETERROR(REG_EBRACK);
1031                 return (0);
1032         }
1033         len = p->next - sp;
1034         for (cp = cnames; cp->name != NULL; cp++)
1035                 if (strncmp(cp->name, sp, len) == 0 && strlen(cp->name) == len)
1036                         return (cp->code);   /* known name */
1037         (void) memset(&mbs, 0, sizeof (mbs));
1038         if ((clen = mbrtowc(&wc, sp, len, &mbs)) == len)
1039                 return (wc);                    /* single character */
1040         else if (clen == (size_t)-1 || clen == (size_t)-2)
1041                 SETERROR(REG_ECHAR);
1042         else
1043                 SETERROR(REG_ECOLLATE);         /* neither */
1044         return (0);
1045 }
1046 
1047 /*
1048  * othercase - return the case counterpart of an alphabetic
1049  */
1050 static wint_t                   /* if no counterpart, return ch */
1051 othercase(wint_t ch)
1052 {
1053         assert(iswalpha(ch));
1054         if (iswupper(ch))
1055                 return (towlower(ch));


1558                                 (void) memset(&mbs, 0, sizeof (mbs));
1559                                 newstart = scan - 1;
1560                         }
1561                         clen = wcrtomb(buf, OPND(s), &mbs);
1562                         if (clen == (size_t)-1)
1563                                 goto toohard;
1564                         newlen += clen;
1565                         break;
1566                 case OPLUS_:            /* things that don't break one */
1567                 case OLPAREN:
1568                 case ORPAREN:
1569                         break;
1570                 case OQUEST_:           /* things that must be skipped */
1571                 case OCH_:
1572                         offset = altoffset(scan, offset);
1573                         scan--;
1574                         do {
1575                                 scan += OPND(s);
1576                                 s = *scan;
1577                                 /* assert() interferes w debug printouts */
1578                                 if (OP(s) != (sop)O_QUEST &&
1579                                     OP(s) != (sop)O_CH && OP(s) != (sop)OOR2) {
1580                                         g->iflags |= BAD;
1581                                         return;
1582                                 }
1583                         } while (OP(s) != (sop)O_QUEST && OP(s) != (sop)O_CH);
1584                         /* FALLTHROUGH */
1585                 case OBOW:              /* things that break a sequence */
1586                 case OEOW:
1587                 case OBOL:
1588                 case OEOL:
1589                 case O_QUEST:
1590                 case O_CH:
1591                 case OEND:
1592                         if (newlen > (sopno)g->mlen) {            /* ends one */
1593                                 start = newstart;
1594                                 g->mlen = newlen;
1595                                 if (offset > -1) {
1596                                         g->moffset += offset;
1597                                         offset = newlen;
1598                                 } else
1599                                         g->moffset = offset;
1600                         } else {
1601                                 if (offset > -1)
1602                                         offset += newlen;
1603                         }
1604                         newlen = 0;
1605                         break;
1606                 case OANY:
1607                         if (newlen > (sopno)g->mlen) {            /* ends one */
1608                                 start = newstart;
1609                                 g->mlen = newlen;
1610                                 if (offset > -1) {
1611                                         g->moffset += offset;
1612                                         offset = newlen;
1613                                 } else
1614                                         g->moffset = offset;
1615                         } else {
1616                                 if (offset > -1)
1617                                         offset += newlen;
1618                         }
1619                         if (offset > -1)
1620                                 offset++;
1621                         newlen = 0;
1622                         break;
1623                 case OANYOF:            /* may or may not invalidate offset */
1624                         /* First, everything as OANY */
1625                         if (newlen > (sopno)g->mlen) {            /* ends one */
1626                                 start = newstart;
1627                                 g->mlen = newlen;
1628                                 if (offset > -1) {
1629                                         g->moffset += offset;
1630                                         offset = newlen;
1631                                 } else
1632                                         g->moffset = offset;
1633                         } else {
1634                                 if (offset > -1)
1635                                         offset += newlen;
1636                         }
1637                         if (offset > -1)
1638                                 offset++;
1639                         newlen = 0;
1640                         break;
1641                 toohard:
1642                 default:
1643                         /*
1644                          * Anything here makes it impossible or too hard
1645                          * to calculate the offset -- so we give up;
1646                          * save the last known good offset, in case the
1647                          * must sequence doesn't occur later.
1648                          */
1649                         if (newlen > (sopno)g->mlen) {            /* ends one */
1650                                 start = newstart;
1651                                 g->mlen = newlen;
1652                                 if (offset > -1)
1653                                         g->moffset += offset;
1654                                 else
1655                                         g->moffset = offset;
1656                         }
1657                         offset = -1;
1658                         newlen = 0;
1659                         break;
1660                 }
1661         } while (OP(s) != OEND);
1662 
1663         if (g->mlen == 0) {          /* there isn't one */
1664                 g->moffset = -1;
1665                 return;
1666         }
1667 
1668         /* turn it into a character string */
1669         g->must = malloc((size_t)g->mlen + 1);


1689 /*
1690  * altoffset - choose biggest offset among multiple choices
1691  *
1692  * Compute, recursively if necessary, the largest offset among multiple
1693  * re paths.
1694  */
1695 static int
1696 altoffset(sop *scan, int offset)
1697 {
1698         int largest;
1699         int try;
1700         sop s;
1701 
1702         /* If we gave up already on offsets, return */
1703         if (offset == -1)
1704                 return (-1);
1705 
1706         largest = 0;
1707         try = 0;
1708         s = *scan++;
1709         while (OP(s) != (sop)O_QUEST && OP(s) != (sop)O_CH) {
1710                 switch (OP(s)) {
1711                 case OOR1:
1712                         if (try > largest)
1713                                 largest = try;
1714                         try = 0;
1715                         break;
1716                 case OQUEST_:
1717                 case OCH_:
1718                         try = altoffset(scan, try);
1719                         if (try == -1)
1720                                 return (-1);
1721                         scan--;
1722                         do {
1723                                 scan += OPND(s);
1724                                 s = *scan;
1725                                 if (OP(s) != (sop)O_QUEST &&
1726                                     OP(s) != (sop)O_CH && OP(s) != (sop)OOR2)
1727                                         return (-1);
1728                         } while (OP(s) != (sop)O_QUEST && OP(s) != (sop)O_CH);
1729                         /*
1730                          * We must skip to the next position, or we'll
1731                          * leave altoffset() too early.
1732                          */
1733                         scan++;
1734                         break;
1735                 case OANYOF:
1736                 case OCHAR:
1737                 case OANY:
1738                         try++;
1739                         /*FALLTHRU*/
1740                 case OBOW:
1741                 case OEOW:
1742                 case OLPAREN:
1743                 case ORPAREN:
1744                 case OOR2:
1745                         break;
1746                 default:
1747                         try = -1;
1748                         break;