LCOV - code coverage report
Current view: top level - src/backend/regex - regcomp.c (source / functions) Hit Total Coverage
Test: PostgreSQL 18devel Lines: 923 952 97.0 %
Date: 2024-11-21 09:14:53 Functions: 35 35 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*
       2             :  * re_*comp and friends - compile REs
       3             :  * This file #includes several others (see the bottom).
       4             :  *
       5             :  * Copyright (c) 1998, 1999 Henry Spencer.  All rights reserved.
       6             :  *
       7             :  * Development of this software was funded, in part, by Cray Research Inc.,
       8             :  * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
       9             :  * Corporation, none of whom are responsible for the results.  The author
      10             :  * thanks all of them.
      11             :  *
      12             :  * Redistribution and use in source and binary forms -- with or without
      13             :  * modification -- are permitted for any purpose, provided that
      14             :  * redistributions in source form retain this entire copyright notice and
      15             :  * indicate the origin and nature of any modifications.
      16             :  *
      17             :  * I'd appreciate being given credit for this package in the documentation
      18             :  * of software which uses it, but that is not a requirement.
      19             :  *
      20             :  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
      21             :  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
      22             :  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
      23             :  * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
      24             :  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
      25             :  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
      26             :  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
      27             :  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
      28             :  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
      29             :  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      30             :  *
      31             :  * src/backend/regex/regcomp.c
      32             :  *
      33             :  */
      34             : 
      35             : #include "regex/regguts.h"
      36             : 
      37             : /*
      38             :  * forward declarations, up here so forward datatypes etc. are defined early
      39             :  */
      40             : /* === regcomp.c === */
      41             : static void moresubs(struct vars *v, int wanted);
      42             : static int  freev(struct vars *v, int err);
      43             : static void makesearch(struct vars *v, struct nfa *nfa);
      44             : static struct subre *parse(struct vars *v, int stopper, int type,
      45             :                            struct state *init, struct state *final);
      46             : static struct subre *parsebranch(struct vars *v, int stopper, int type,
      47             :                                  struct state *left, struct state *right,
      48             :                                  int partial);
      49             : static struct subre *parseqatom(struct vars *v, int stopper, int type,
      50             :                                 struct state *lp, struct state *rp,
      51             :                                 struct subre *top);
      52             : static void nonword(struct vars *v, int dir, struct state *lp,
      53             :                     struct state *rp);
      54             : static void word(struct vars *v, int dir, struct state *lp, struct state *rp);
      55             : static void charclass(struct vars *v, enum char_classes cls, struct state *lp,
      56             :                       struct state *rp);
      57             : static void charclasscomplement(struct vars *v, enum char_classes cls,
      58             :                                 struct state *lp, struct state *rp);
      59             : static int  scannum(struct vars *v);
      60             : static void repeat(struct vars *v, struct state *lp, struct state *rp,
      61             :                    int m, int n);
      62             : static void bracket(struct vars *v, struct state *lp, struct state *rp);
      63             : static void cbracket(struct vars *v, struct state *lp, struct state *rp);
      64             : static void brackpart(struct vars *v, struct state *lp, struct state *rp,
      65             :                       bool *have_cclassc);
      66             : static const chr *scanplain(struct vars *v);
      67             : static void onechr(struct vars *v, chr c, struct state *lp, struct state *rp);
      68             : static void optimizebracket(struct vars *v, struct state *lp, struct state *rp);
      69             : static void wordchrs(struct vars *v);
      70             : static void processlacon(struct vars *v, struct state *begin,
      71             :                          struct state *end, int latype,
      72             :                          struct state *lp, struct state *rp);
      73             : static struct subre *subre(struct vars *v, int op, int flags,
      74             :                            struct state *begin, struct state *end);
      75             : static void freesubre(struct vars *v, struct subre *sr);
      76             : static void freesubreandsiblings(struct vars *v, struct subre *sr);
      77             : static void freesrnode(struct vars *v, struct subre *sr);
      78             : static void removecaptures(struct vars *v, struct subre *t);
      79             : static int  numst(struct subre *t, int start);
      80             : static void markst(struct subre *t);
      81             : static void cleanst(struct vars *v);
      82             : static long nfatree(struct vars *v, struct subre *t, FILE *f);
      83             : static long nfanode(struct vars *v, struct subre *t,
      84             :                     int converttosearch, FILE *f);
      85             : static int  newlacon(struct vars *v, struct state *begin, struct state *end,
      86             :                      int latype);
      87             : static void freelacons(struct subre *subs, int n);
      88             : static void rfree(regex_t *re);
      89             : static int  rstacktoodeep(void);
      90             : 
      91             : #ifdef REG_DEBUG
      92             : static void dump(regex_t *re, FILE *f);
      93             : static void dumpst(struct subre *t, FILE *f, int nfapresent);
      94             : static void stdump(struct subre *t, FILE *f, int nfapresent);
      95             : static const char *stid(struct subre *t, char *buf, size_t bufsize);
      96             : #endif
      97             : /* === regc_lex.c === */
      98             : static void lexstart(struct vars *v);
      99             : static void prefixes(struct vars *v);
     100             : static int  next(struct vars *v);
     101             : static int  lexescape(struct vars *v);
     102             : static chr  lexdigits(struct vars *v, int base, int minlen, int maxlen);
     103             : static int  brenext(struct vars *v, chr c);
     104             : static void skip(struct vars *v);
     105             : static chr  newline(void);
     106             : static chr  chrnamed(struct vars *v, const chr *startp, const chr *endp,
     107             :                      chr lastresort);
     108             : 
     109             : /* === regc_color.c === */
     110             : static void initcm(struct vars *v, struct colormap *cm);
     111             : static void freecm(struct colormap *cm);
     112             : static color maxcolor(struct colormap *cm);
     113             : static color newcolor(struct colormap *cm);
     114             : static void freecolor(struct colormap *cm, color co);
     115             : static color pseudocolor(struct colormap *cm);
     116             : static color subcolor(struct colormap *cm, chr c);
     117             : static color subcolorhi(struct colormap *cm, color *pco);
     118             : static color newsub(struct colormap *cm, color co);
     119             : static int  newhicolorrow(struct colormap *cm, int oldrow);
     120             : static void newhicolorcols(struct colormap *cm);
     121             : static void subcolorcvec(struct vars *v, struct cvec *cv, struct state *lp,
     122             :                          struct state *rp);
     123             : static void subcoloronechr(struct vars *v, chr ch, struct state *lp,
     124             :                            struct state *rp, color *lastsubcolor);
     125             : static void subcoloronerange(struct vars *v, chr from, chr to,
     126             :                              struct state *lp, struct state *rp,
     127             :                              color *lastsubcolor);
     128             : static void subcoloronerow(struct vars *v, int rownum, struct state *lp,
     129             :                            struct state *rp, color *lastsubcolor);
     130             : static void okcolors(struct nfa *nfa, struct colormap *cm);
     131             : static void colorchain(struct colormap *cm, struct arc *a);
     132             : static void uncolorchain(struct colormap *cm, struct arc *a);
     133             : static void rainbow(struct nfa *nfa, struct colormap *cm, int type, color but,
     134             :                     struct state *from, struct state *to);
     135             : static void colorcomplement(struct nfa *nfa, struct colormap *cm, int type,
     136             :                             struct state *of, struct state *from,
     137             :                             struct state *to);
     138             : 
     139             : #ifdef REG_DEBUG
     140             : static void dumpcolors(struct colormap *cm, FILE *f);
     141             : static void dumpchr(chr c, FILE *f);
     142             : #endif
     143             : /* === regc_nfa.c === */
     144             : static struct nfa *newnfa(struct vars *v, struct colormap *cm,
     145             :                           struct nfa *parent);
     146             : static void freenfa(struct nfa *nfa);
     147             : static struct state *newstate(struct nfa *nfa);
     148             : static struct state *newfstate(struct nfa *nfa, int flag);
     149             : static void dropstate(struct nfa *nfa, struct state *s);
     150             : static void freestate(struct nfa *nfa, struct state *s);
     151             : static void newarc(struct nfa *nfa, int t, color co,
     152             :                    struct state *from, struct state *to);
     153             : static void createarc(struct nfa *nfa, int t, color co,
     154             :                       struct state *from, struct state *to);
     155             : static struct arc *allocarc(struct nfa *nfa);
     156             : static void freearc(struct nfa *nfa, struct arc *victim);
     157             : static void changearcsource(struct arc *a, struct state *newfrom);
     158             : static void changearctarget(struct arc *a, struct state *newto);
     159             : static int  hasnonemptyout(struct state *s);
     160             : static struct arc *findarc(struct state *s, int type, color co);
     161             : static void cparc(struct nfa *nfa, struct arc *oa,
     162             :                   struct state *from, struct state *to);
     163             : static void sortins(struct nfa *nfa, struct state *s);
     164             : static int  sortins_cmp(const void *a, const void *b);
     165             : static void sortouts(struct nfa *nfa, struct state *s);
     166             : static int  sortouts_cmp(const void *a, const void *b);
     167             : static void moveins(struct nfa *nfa, struct state *oldState,
     168             :                     struct state *newState);
     169             : static void copyins(struct nfa *nfa, struct state *oldState,
     170             :                     struct state *newState);
     171             : static void mergeins(struct nfa *nfa, struct state *s,
     172             :                      struct arc **arcarray, int arccount);
     173             : static void moveouts(struct nfa *nfa, struct state *oldState,
     174             :                      struct state *newState);
     175             : static void copyouts(struct nfa *nfa, struct state *oldState,
     176             :                      struct state *newState);
     177             : static void cloneouts(struct nfa *nfa, struct state *old, struct state *from,
     178             :                       struct state *to, int type);
     179             : static void delsub(struct nfa *nfa, struct state *lp, struct state *rp);
     180             : static void deltraverse(struct nfa *nfa, struct state *leftend,
     181             :                         struct state *s);
     182             : static void dupnfa(struct nfa *nfa, struct state *start, struct state *stop,
     183             :                    struct state *from, struct state *to);
     184             : static void duptraverse(struct nfa *nfa, struct state *s, struct state *stmp);
     185             : static void removeconstraints(struct nfa *nfa, struct state *start, struct state *stop);
     186             : static void removetraverse(struct nfa *nfa, struct state *s);
     187             : static void cleartraverse(struct nfa *nfa, struct state *s);
     188             : static struct state *single_color_transition(struct state *s1,
     189             :                                              struct state *s2);
     190             : static void specialcolors(struct nfa *nfa);
     191             : static long optimize(struct nfa *nfa, FILE *f);
     192             : static void pullback(struct nfa *nfa, FILE *f);
     193             : static int  pull(struct nfa *nfa, struct arc *con,
     194             :                  struct state **intermediates);
     195             : static void pushfwd(struct nfa *nfa, FILE *f);
     196             : static int  push(struct nfa *nfa, struct arc *con,
     197             :                  struct state **intermediates);
     198             : 
     199             : #define INCOMPATIBLE    1       /* destroys arc */
     200             : #define SATISFIED   2           /* constraint satisfied */
     201             : #define COMPATIBLE  3           /* compatible but not satisfied yet */
     202             : #define REPLACEARC  4           /* replace arc's color with constraint color */
     203             : static int  combine(struct nfa *nfa, struct arc *con, struct arc *a);
     204             : static void fixempties(struct nfa *nfa, FILE *f);
     205             : static struct state *emptyreachable(struct nfa *nfa, struct state *s,
     206             :                                     struct state *lastfound,
     207             :                                     struct arc **inarcsorig);
     208             : static int  isconstraintarc(struct arc *a);
     209             : static int  hasconstraintout(struct state *s);
     210             : static void fixconstraintloops(struct nfa *nfa, FILE *f);
     211             : static int  findconstraintloop(struct nfa *nfa, struct state *s);
     212             : static void breakconstraintloop(struct nfa *nfa, struct state *sinitial);
     213             : static void clonesuccessorstates(struct nfa *nfa, struct state *ssource,
     214             :                                  struct state *sclone,
     215             :                                  struct state *spredecessor,
     216             :                                  struct arc *refarc, char *curdonemap,
     217             :                                  char *outerdonemap, int nstates);
     218             : static void removecantmatch(struct nfa *nfa);
     219             : static void cleanup(struct nfa *nfa);
     220             : static void markreachable(struct nfa *nfa, struct state *s,
     221             :                           struct state *okay, struct state *mark);
     222             : static void markcanreach(struct nfa *nfa, struct state *s, struct state *okay,
     223             :                          struct state *mark);
     224             : static long analyze(struct nfa *nfa);
     225             : static void checkmatchall(struct nfa *nfa);
     226             : static bool checkmatchall_recurse(struct nfa *nfa, struct state *s,
     227             :                                   bool **haspaths);
     228             : static bool check_out_colors_match(struct state *s, color co1, color co2);
     229             : static bool check_in_colors_match(struct state *s, color co1, color co2);
     230             : static void compact(struct nfa *nfa, struct cnfa *cnfa);
     231             : static void carcsort(struct carc *first, size_t n);
     232             : static int  carc_cmp(const void *a, const void *b);
     233             : static void freecnfa(struct cnfa *cnfa);
     234             : static void dumpnfa(struct nfa *nfa, FILE *f);
     235             : 
     236             : #ifdef REG_DEBUG
     237             : static void dumpstate(struct state *s, FILE *f);
     238             : static void dumparcs(struct state *s, FILE *f);
     239             : static void dumparc(struct arc *a, struct state *s, FILE *f);
     240             : static void dumpcnfa(struct cnfa *cnfa, FILE *f);
     241             : static void dumpcstate(int st, struct cnfa *cnfa, FILE *f);
     242             : #endif
     243             : /* === regc_cvec.c === */
     244             : static struct cvec *newcvec(int nchrs, int nranges);
     245             : static struct cvec *clearcvec(struct cvec *cv);
     246             : static void addchr(struct cvec *cv, chr c);
     247             : static void addrange(struct cvec *cv, chr from, chr to);
     248             : static struct cvec *getcvec(struct vars *v, int nchrs, int nranges);
     249             : static void freecvec(struct cvec *cv);
     250             : 
     251             : /* === regc_pg_locale.c === */
     252             : static int  pg_wc_isdigit(pg_wchar c);
     253             : static int  pg_wc_isalpha(pg_wchar c);
     254             : static int  pg_wc_isalnum(pg_wchar c);
     255             : static int  pg_wc_isword(pg_wchar c);
     256             : static int  pg_wc_isupper(pg_wchar c);
     257             : static int  pg_wc_islower(pg_wchar c);
     258             : static int  pg_wc_isgraph(pg_wchar c);
     259             : static int  pg_wc_isprint(pg_wchar c);
     260             : static int  pg_wc_ispunct(pg_wchar c);
     261             : static int  pg_wc_isspace(pg_wchar c);
     262             : static pg_wchar pg_wc_toupper(pg_wchar c);
     263             : static pg_wchar pg_wc_tolower(pg_wchar c);
     264             : 
     265             : /* === regc_locale.c === */
     266             : static chr  element(struct vars *v, const chr *startp, const chr *endp);
     267             : static struct cvec *range(struct vars *v, chr a, chr b, int cases);
     268             : static int  before(chr x, chr y);
     269             : static struct cvec *eclass(struct vars *v, chr c, int cases);
     270             : static enum char_classes lookupcclass(struct vars *v, const chr *startp,
     271             :                                       const chr *endp);
     272             : static struct cvec *cclasscvec(struct vars *v, enum char_classes cclasscode,
     273             :                                int cases);
     274             : static int  cclass_column_index(struct colormap *cm, chr c);
     275             : static struct cvec *allcases(struct vars *v, chr c);
     276             : static int  cmp(const chr *x, const chr *y, size_t len);
     277             : static int  casecmp(const chr *x, const chr *y, size_t len);
     278             : 
     279             : 
     280             : /* internal variables, bundled for easy passing around */
     281             : struct vars
     282             : {
     283             :     regex_t    *re;
     284             :     const chr  *now;            /* scan pointer into string */
     285             :     const chr  *stop;           /* end of string */
     286             :     int         err;            /* error code (0 if none) */
     287             :     int         cflags;         /* copy of compile flags */
     288             :     int         lasttype;       /* type of previous token */
     289             :     int         nexttype;       /* type of next token */
     290             :     chr         nextvalue;      /* value (if any) of next token */
     291             :     int         lexcon;         /* lexical context type (see regc_lex.c) */
     292             :     int         nsubexp;        /* subexpression count */
     293             :     struct subre **subs;        /* subRE pointer vector */
     294             :     size_t      nsubs;          /* length of vector */
     295             :     struct subre *sub10[10];    /* initial vector, enough for most */
     296             :     struct nfa *nfa;            /* the NFA */
     297             :     struct colormap *cm;        /* character color map */
     298             :     color       nlcolor;        /* color of newline */
     299             :     struct state *wordchrs;     /* state in nfa holding word-char outarcs */
     300             :     struct subre *tree;         /* subexpression tree */
     301             :     struct subre *treechain;    /* all tree nodes allocated */
     302             :     struct subre *treefree;     /* any free tree nodes */
     303             :     int         ntree;          /* number of tree nodes, plus one */
     304             :     struct cvec *cv;            /* interface cvec */
     305             :     struct cvec *cv2;           /* utility cvec */
     306             :     struct subre *lacons;       /* lookaround-constraint vector */
     307             :     int         nlacons;        /* size of lacons[]; note that only slots
     308             :                                  * numbered 1 .. nlacons-1 are used */
     309             :     size_t      spaceused;      /* approx. space used for compilation */
     310             : };
     311             : 
     312             : /* parsing macros; most know that `v' is the struct vars pointer */
     313             : #define NEXT()  (next(v))       /* advance by one token */
     314             : #define SEE(t)  (v->nexttype == (t)) /* is next token this? */
     315             : #define EAT(t)  (SEE(t) && next(v)) /* if next is this, swallow it */
     316             : #define VISERR(vv)  ((vv)->err != 0) /* have we seen an error yet? */
     317             : #define ISERR() VISERR(v)
     318             : #define VERR(vv,e)  ((vv)->nexttype = EOS, \
     319             :                      (vv)->err = ((vv)->err ? (vv)->err : (e)))
     320             : #define ERR(e)  VERR(v, e)      /* record an error */
     321             : #define NOERR() {if (ISERR()) return;}  /* if error seen, return */
     322             : #define NOERRN()    {if (ISERR()) return NULL;} /* NOERR with retval */
     323             : #define NOERRZ()    {if (ISERR()) return 0;}    /* NOERR with retval */
     324             : #define INSIST(c, e) do { if (!(c)) ERR(e); } while (0) /* error if c false */
     325             : #define NOTE(b) (v->re->re_info |= (b)) /* note visible condition */
     326             : #define EMPTYARC(x, y)  newarc(v->nfa, EMPTY, 0, x, y)
     327             : 
     328             : /* token type codes, some also used as NFA arc types */
     329             : #define EMPTY   'n'             /* no token present */
     330             : #define EOS 'e'                 /* end of string */
     331             : #define PLAIN   'p'             /* ordinary character */
     332             : #define DIGIT   'd'             /* digit (in bound) */
     333             : #define BACKREF 'b'             /* back reference */
     334             : #define COLLEL  'I'             /* start of [. */
     335             : #define ECLASS  'E'             /* start of [= */
     336             : #define CCLASS  'C'             /* start of [: */
     337             : #define END 'X'                 /* end of [. [= [: */
     338             : #define CCLASSS 's'             /* char class shorthand escape */
     339             : #define CCLASSC 'c'             /* complement char class shorthand escape */
     340             : #define RANGE   'R'             /* - within [] which might be range delim. */
     341             : #define LACON   'L'             /* lookaround constraint subRE */
     342             : #define AHEAD   'a'             /* color-lookahead arc */
     343             : #define BEHIND  'r'             /* color-lookbehind arc */
     344             : #define WBDRY   'w'             /* word boundary constraint */
     345             : #define NWBDRY  'W'             /* non-word-boundary constraint */
     346             : #define CANTMATCH 'x'           /* arc that cannot match anything */
     347             : #define SBEGIN  'A'             /* beginning of string (even if not BOL) */
     348             : #define SEND    'Z'             /* end of string (even if not EOL) */
     349             : 
     350             : /* is an arc colored, and hence should belong to a color chain? */
     351             : /* the test on "co" eliminates RAINBOW arcs, which we don't bother to chain */
     352             : #define COLORED(a) \
     353             :     ((a)->co >= 0 && \
     354             :      ((a)->type == PLAIN || (a)->type == AHEAD || (a)->type == BEHIND))
     355             : 
     356             : 
     357             : /* static function list */
     358             : static const struct fns functions = {
     359             :     rfree,                      /* regfree insides */
     360             :     rstacktoodeep               /* check for stack getting dangerously deep */
     361             : };
     362             : 
     363             : 
     364             : 
     365             : /*
     366             :  * pg_regcomp - compile regular expression
     367             :  *
     368             :  * Note: on failure, no resources remain allocated, so pg_regfree()
     369             :  * need not be applied to re.
     370             :  */
     371             : int
     372        7420 : pg_regcomp(regex_t *re,
     373             :            const chr *string,
     374             :            size_t len,
     375             :            int flags,
     376             :            Oid collation)
     377             : {
     378             :     struct vars var;
     379        7420 :     struct vars *v = &var;
     380             :     struct guts *g;
     381             :     int         i;
     382             :     size_t      j;
     383             : 
     384             : #ifdef REG_DEBUG
     385             :     FILE       *debug = (flags & REG_PROGRESS) ? stdout : (FILE *) NULL;
     386             : #else
     387        7420 :     FILE       *debug = (FILE *) NULL;
     388             : #endif
     389             : 
     390             : #define  CNOERR()    { if (ISERR()) return freev(v, v->err); }
     391             : 
     392             :     /* sanity checks */
     393             : 
     394        7420 :     if (re == NULL || string == NULL)
     395           0 :         return REG_INVARG;
     396        7420 :     if ((flags & REG_QUOTE) &&
     397          90 :         (flags & (REG_ADVANCED | REG_EXPANDED | REG_NEWLINE)))
     398           8 :         return REG_INVARG;
     399        7412 :     if (!(flags & REG_EXTENDED) && (flags & REG_ADVF))
     400           2 :         return REG_INVARG;
     401             : 
     402             :     /* Initialize locale-dependent support */
     403        7410 :     pg_set_regex_collation(collation);
     404             : 
     405             :     /* initial setup (after which freev() is callable) */
     406        7386 :     v->re = re;
     407        7386 :     v->now = string;
     408        7386 :     v->stop = v->now + len;
     409        7386 :     v->err = 0;
     410        7386 :     v->cflags = flags;
     411        7386 :     v->nsubexp = 0;
     412        7386 :     v->subs = v->sub10;
     413        7386 :     v->nsubs = 10;
     414       81246 :     for (j = 0; j < v->nsubs; j++)
     415       73860 :         v->subs[j] = NULL;
     416        7386 :     v->nfa = NULL;
     417        7386 :     v->cm = NULL;
     418        7386 :     v->nlcolor = COLORLESS;
     419        7386 :     v->wordchrs = NULL;
     420        7386 :     v->tree = NULL;
     421        7386 :     v->treechain = NULL;
     422        7386 :     v->treefree = NULL;
     423        7386 :     v->cv = NULL;
     424        7386 :     v->cv2 = NULL;
     425        7386 :     v->lacons = NULL;
     426        7386 :     v->nlacons = 0;
     427        7386 :     v->spaceused = 0;
     428        7386 :     re->re_magic = REMAGIC;
     429        7386 :     re->re_info = 0;         /* bits get set during parse */
     430        7386 :     re->re_csize = sizeof(chr);
     431        7386 :     re->re_collation = collation;
     432        7386 :     re->re_guts = NULL;
     433        7386 :     re->re_fns = VS(&functions);
     434             : 
     435             :     /* more complex setup, malloced things */
     436        7386 :     re->re_guts = VS(MALLOC(sizeof(struct guts)));
     437        7386 :     if (re->re_guts == NULL)
     438           0 :         return freev(v, REG_ESPACE);
     439        7386 :     g = (struct guts *) re->re_guts;
     440        7386 :     g->tree = NULL;
     441        7386 :     initcm(v, &g->cmap);
     442        7386 :     v->cm = &g->cmap;
     443        7386 :     g->lacons = NULL;
     444        7386 :     g->nlacons = 0;
     445        7386 :     ZAPCNFA(g->search);
     446        7386 :     v->nfa = newnfa(v, v->cm, (struct nfa *) NULL);
     447        7386 :     CNOERR();
     448             :     /* set up a reasonably-sized transient cvec for getcvec usage */
     449        7386 :     v->cv = newcvec(100, 20);
     450        7386 :     if (v->cv == NULL)
     451           0 :         return freev(v, REG_ESPACE);
     452             : 
     453             :     /* parsing */
     454        7386 :     lexstart(v);                /* also handles prefixes */
     455        7386 :     if ((v->cflags & REG_NLSTOP) || (v->cflags & REG_NLANCH))
     456             :     {
     457             :         /* assign newline a unique color */
     458         572 :         v->nlcolor = subcolor(v->cm, newline());
     459         572 :         okcolors(v->nfa, v->cm);
     460             :     }
     461        7386 :     CNOERR();
     462        7372 :     v->tree = parse(v, EOS, PLAIN, v->nfa->init, v->nfa->final);
     463             :     assert(SEE(EOS));           /* even if error; ISERR() => SEE(EOS) */
     464        7372 :     CNOERR();
     465             :     assert(v->tree != NULL);
     466             : 
     467             :     /* finish setup of nfa and its subre tree */
     468        7148 :     specialcolors(v->nfa);
     469        7148 :     CNOERR();
     470             : #ifdef REG_DEBUG
     471             :     if (debug != NULL)
     472             :     {
     473             :         fprintf(debug, "\n\n\n========= RAW ==========\n");
     474             :         dumpnfa(v->nfa, debug);
     475             :         dumpst(v->tree, debug, 1);
     476             :     }
     477             : #endif
     478        7148 :     if (v->cflags & REG_NOSUB)
     479        5238 :         removecaptures(v, v->tree);
     480        7148 :     v->ntree = numst(v->tree, 1);
     481        7148 :     markst(v->tree);
     482        7148 :     cleanst(v);
     483             : #ifdef REG_DEBUG
     484             :     if (debug != NULL)
     485             :     {
     486             :         fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
     487             :         dumpst(v->tree, debug, 1);
     488             :     }
     489             : #endif
     490             : 
     491             :     /* build compacted NFAs for tree and lacons */
     492        7148 :     re->re_info |= nfatree(v, v->tree, debug);
     493        7148 :     CNOERR();
     494             :     assert(v->nlacons == 0 || v->lacons != NULL);
     495        7228 :     for (i = 1; i < v->nlacons; i++)
     496             :     {
     497          86 :         struct subre *lasub = &v->lacons[i];
     498             : 
     499             : #ifdef REG_DEBUG
     500             :         if (debug != NULL)
     501             :             fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
     502             : #endif
     503             : 
     504             :         /* Prepend .* to pattern if it's a lookbehind LACON */
     505          86 :         nfanode(v, lasub, !LATYPE_IS_AHEAD(lasub->latype), debug);
     506             :     }
     507        7142 :     CNOERR();
     508        7142 :     if (v->tree->flags & SHORTER)
     509         140 :         NOTE(REG_USHORTEST);
     510             : 
     511             :     /* build compacted NFAs for tree, lacons, fast search */
     512             : #ifdef REG_DEBUG
     513             :     if (debug != NULL)
     514             :         fprintf(debug, "\n\n\n========= SEARCH ==========\n");
     515             : #endif
     516             :     /* can sacrifice main NFA now, so use it as work area */
     517        7142 :     (DISCARD) optimize(v->nfa, debug);
     518        7142 :     CNOERR();
     519        7142 :     makesearch(v, v->nfa);
     520        7142 :     CNOERR();
     521        7142 :     compact(v->nfa, &g->search);
     522        7142 :     CNOERR();
     523             : 
     524             :     /* looks okay, package it up */
     525        7142 :     re->re_nsub = v->nsubexp;
     526        7142 :     v->re = NULL;                /* freev no longer frees re */
     527        7142 :     g->magic = GUTSMAGIC;
     528        7142 :     g->cflags = v->cflags;
     529        7142 :     g->info = re->re_info;
     530        7142 :     g->nsub = re->re_nsub;
     531        7142 :     g->tree = v->tree;
     532        7142 :     v->tree = NULL;
     533        7142 :     g->ntree = v->ntree;
     534        7142 :     g->compare = (v->cflags & REG_ICASE) ? casecmp : cmp;
     535        7142 :     g->lacons = v->lacons;
     536        7142 :     v->lacons = NULL;
     537        7142 :     g->nlacons = v->nlacons;
     538             : 
     539             : #ifdef REG_DEBUG
     540             :     if (flags & REG_DUMP)
     541             :     {
     542             :         dump(re, stdout);
     543             :         fflush(stdout);
     544             :     }
     545             : #endif
     546             : 
     547             :     assert(v->err == 0);
     548        7142 :     return freev(v, 0);
     549             : }
     550             : 
     551             : /*
     552             :  * moresubs - enlarge subRE vector
     553             :  */
     554             : static void
     555          24 : moresubs(struct vars *v,
     556             :          int wanted)            /* want enough room for this one */
     557             : {
     558             :     struct subre **p;
     559             :     size_t      n;
     560             : 
     561             :     assert(wanted > 0 && (size_t) wanted >= v->nsubs);
     562          24 :     n = (size_t) wanted * 3 / 2 + 1;
     563             : 
     564          24 :     if (v->subs == v->sub10)
     565             :     {
     566          12 :         p = (struct subre **) MALLOC(n * sizeof(struct subre *));
     567          12 :         if (p != NULL)
     568          12 :             memcpy(VS(p), VS(v->subs),
     569          12 :                    v->nsubs * sizeof(struct subre *));
     570             :     }
     571             :     else
     572          12 :         p = (struct subre **) REALLOC(v->subs, n * sizeof(struct subre *));
     573          24 :     if (p == NULL)
     574             :     {
     575           0 :         ERR(REG_ESPACE);
     576           0 :         return;
     577             :     }
     578          24 :     v->subs = p;
     579         284 :     for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++)
     580         260 :         *p = NULL;
     581             :     assert(v->nsubs == n);
     582             :     assert((size_t) wanted < v->nsubs);
     583             : }
     584             : 
     585             : /*
     586             :  * freev - free vars struct's substructures where necessary
     587             :  *
     588             :  * Optionally does error-number setting, and always returns error code
     589             :  * (if any), to make error-handling code terser.
     590             :  */
     591             : static int
     592        7386 : freev(struct vars *v,
     593             :       int err)
     594             : {
     595        7386 :     if (v->re != NULL)
     596         244 :         rfree(v->re);
     597        7386 :     if (v->subs != v->sub10)
     598          12 :         FREE(v->subs);
     599        7386 :     if (v->nfa != NULL)
     600        7386 :         freenfa(v->nfa);
     601        7386 :     if (v->tree != NULL)
     602           6 :         freesubre(v, v->tree);
     603        7386 :     if (v->treechain != NULL)
     604         224 :         cleanst(v);
     605        7386 :     if (v->cv != NULL)
     606        7386 :         freecvec(v->cv);
     607        7386 :     if (v->cv2 != NULL)
     608           0 :         freecvec(v->cv2);
     609        7386 :     if (v->lacons != NULL)
     610           0 :         freelacons(v->lacons, v->nlacons);
     611        7386 :     ERR(err);                   /* nop if err==0 */
     612             : 
     613        7386 :     return v->err;
     614             : }
     615             : 
     616             : /*
     617             :  * makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
     618             :  * NFA must have been optimize()d already.
     619             :  */
     620             : static void
     621        7160 : makesearch(struct vars *v,
     622             :            struct nfa *nfa)
     623             : {
     624             :     struct arc *a;
     625             :     struct arc *b;
     626        7160 :     struct state *pre = nfa->pre;
     627             :     struct state *s;
     628             :     struct state *s2;
     629             :     struct state *slist;
     630             : 
     631             :     /* no loops are needed if it's anchored */
     632       21072 :     for (a = pre->outs; a != NULL; a = a->outchain)
     633             :     {
     634             :         assert(a->type == PLAIN);
     635       16814 :         if (a->co != nfa->bos[0] && a->co != nfa->bos[1])
     636        2902 :             break;
     637             :     }
     638        7160 :     if (a != NULL)
     639             :     {
     640             :         /* add implicit .* in front */
     641        2902 :         rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre);
     642             : 
     643             :         /* and ^* and \A* too -- not always necessary, but harmless */
     644        2902 :         newarc(nfa, PLAIN, nfa->bos[0], pre, pre);
     645        2902 :         newarc(nfa, PLAIN, nfa->bos[1], pre, pre);
     646             : 
     647             :         /*
     648             :          * The pattern is still MATCHALL if it was before, but the max match
     649             :          * length is now infinity.
     650             :          */
     651        2902 :         if (nfa->flags & MATCHALL)
     652         132 :             nfa->maxmatchall = DUPINF;
     653             :     }
     654             : 
     655             :     /*
     656             :      * Now here's the subtle part.  Because many REs have no lookback
     657             :      * constraints, often knowing when you were in the pre state tells you
     658             :      * little; it's the next state(s) that are informative.  But some of them
     659             :      * may have other inarcs, i.e. it may be possible to make actual progress
     660             :      * and then return to one of them.  We must de-optimize such cases,
     661             :      * splitting each such state into progress and no-progress states.
     662             :      */
     663             : 
     664             :     /* first, make a list of the states reachable from pre and elsewhere */
     665        7160 :     slist = NULL;
     666       34832 :     for (a = pre->outs; a != NULL; a = a->outchain)
     667             :     {
     668       27672 :         s = a->to;
     669       94574 :         for (b = s->ins; b != NULL; b = b->inchain)
     670             :         {
     671       74694 :             if (b->from != pre)
     672        7792 :                 break;
     673             :         }
     674             : 
     675             :         /*
     676             :          * We want to mark states as being in the list already by having non
     677             :          * NULL tmp fields, but we can't just store the old slist value in tmp
     678             :          * because that doesn't work for the first such state.  Instead, the
     679             :          * first list entry gets its own address in tmp.
     680             :          */
     681       27672 :         if (b != NULL && s->tmp == NULL)
     682             :         {
     683        2940 :             s->tmp = (slist != NULL) ? slist : s;
     684        2940 :             slist = s;
     685             :         }
     686             :     }
     687             : 
     688             :     /* do the splits */
     689       10100 :     for (s = slist; s != NULL; s = s2)
     690             :     {
     691        2940 :         s2 = newstate(nfa);
     692        2940 :         NOERR();
     693        2940 :         copyouts(nfa, s, s2);
     694        2940 :         NOERR();
     695      441864 :         for (a = s->ins; a != NULL; a = b)
     696             :         {
     697      438924 :             b = a->inchain;
     698      438924 :             if (a->from != pre)
     699             :             {
     700      431132 :                 cparc(nfa, a, a->from, s2);
     701      431132 :                 freearc(nfa, a);
     702             :             }
     703             :         }
     704        2940 :         s2 = (s->tmp != s) ? s->tmp : NULL;
     705        2940 :         s->tmp = NULL;           /* clean up while we're at it */
     706             :     }
     707             : }
     708             : 
     709             : /*
     710             :  * parse - parse an RE
     711             :  *
     712             :  * This is actually just the top level, which parses a bunch of branches
     713             :  * tied together with '|'.  If there's more than one, they appear in the
     714             :  * tree as the children of a '|' subre.
     715             :  */
     716             : static struct subre *
     717       12632 : parse(struct vars *v,
     718             :       int stopper,              /* EOS or ')' */
     719             :       int type,                 /* LACON (lookaround subRE) or PLAIN */
     720             :       struct state *init,       /* initial state */
     721             :       struct state *final)      /* final state */
     722             : {
     723             :     struct subre *branches;     /* top level */
     724             :     struct subre *lastbranch;   /* latest branch */
     725             : 
     726             :     assert(stopper == ')' || stopper == EOS);
     727             : 
     728       12632 :     branches = subre(v, '|', LONGER, init, final);
     729       12632 :     NOERRN();
     730       12632 :     lastbranch = NULL;
     731             :     do
     732             :     {                           /* a branch */
     733             :         struct subre *branch;
     734             :         struct state *left;     /* scaffolding for branch */
     735             :         struct state *right;
     736             : 
     737       13254 :         left = newstate(v->nfa);
     738       13254 :         right = newstate(v->nfa);
     739       13254 :         NOERRN();
     740       13254 :         EMPTYARC(init, left);
     741       13254 :         EMPTYARC(right, final);
     742       13254 :         NOERRN();
     743       13254 :         branch = parsebranch(v, stopper, type, left, right, 0);
     744       13254 :         NOERRN();
     745       12978 :         if (lastbranch)
     746         622 :             lastbranch->sibling = branch;
     747             :         else
     748       12356 :             branches->child = branch;
     749       12978 :         branches->flags |= UP(branches->flags | branch->flags);
     750       12978 :         lastbranch = branch;
     751       12978 :     } while (EAT('|'));
     752             :     assert(SEE(stopper) || SEE(EOS));
     753             : 
     754       12356 :     if (!SEE(stopper))
     755             :     {
     756             :         assert(stopper == ')' && SEE(EOS));
     757          16 :         ERR(REG_EPAREN);
     758             :     }
     759             : 
     760             :     /* optimize out simple cases */
     761       12356 :     if (lastbranch == branches->child)
     762             :     {                           /* only one branch */
     763             :         assert(lastbranch->sibling == NULL);
     764       11988 :         freesrnode(v, branches);
     765       11988 :         branches = lastbranch;
     766             :     }
     767         368 :     else if (!MESSY(branches->flags))
     768             :     {                           /* no interesting innards */
     769         204 :         freesubreandsiblings(v, branches->child);
     770         204 :         branches->child = NULL;
     771         204 :         branches->op = '=';
     772             :     }
     773             : 
     774       12356 :     return branches;
     775             : }
     776             : 
     777             : /*
     778             :  * parsebranch - parse one branch of an RE
     779             :  *
     780             :  * This mostly manages concatenation, working closely with parseqatom().
     781             :  * Concatenated things are bundled up as much as possible, with separate
     782             :  * '.' nodes introduced only when necessary due to substructure.
     783             :  */
     784             : static struct subre *
     785       17448 : parsebranch(struct vars *v,
     786             :             int stopper,        /* EOS or ')' */
     787             :             int type,           /* LACON (lookaround subRE) or PLAIN */
     788             :             struct state *left, /* leftmost state */
     789             :             struct state *right,    /* rightmost state */
     790             :             int partial)        /* is this only part of a branch? */
     791             : {
     792             :     struct state *lp;           /* left end of current construct */
     793             :     int         seencontent;    /* is there anything in this branch yet? */
     794             :     struct subre *t;
     795             : 
     796       17448 :     lp = left;
     797       17448 :     seencontent = 0;
     798       17448 :     t = subre(v, '=', 0, left, right);  /* op '=' is tentative */
     799       17448 :     NOERRN();
     800      111604 :     while (!SEE('|') && !SEE(stopper) && !SEE(EOS))
     801             :     {
     802       94456 :         if (seencontent)
     803             :         {                       /* implicit concat operator */
     804       77208 :             lp = newstate(v->nfa);
     805       77208 :             NOERRN();
     806       77208 :             moveins(v->nfa, right, lp);
     807             :         }
     808       94456 :         seencontent = 1;
     809             : 
     810             :         /* NB, recursion in parseqatom() may swallow rest of branch */
     811       94456 :         t = parseqatom(v, stopper, type, lp, right, t);
     812       94456 :         NOERRN();
     813             :     }
     814             : 
     815       17148 :     if (!seencontent)
     816             :     {                           /* empty branch */
     817         200 :         if (!partial)
     818         200 :             NOTE(REG_UUNSPEC);
     819             :         assert(lp == left);
     820         200 :         EMPTYARC(left, right);
     821             :     }
     822             : 
     823       17148 :     return t;
     824             : }
     825             : 
     826             : /*
     827             :  * parseqatom - parse one quantified atom or constraint of an RE
     828             :  *
     829             :  * The bookkeeping near the end cooperates very closely with parsebranch();
     830             :  * in particular, it contains a recursion that can involve parsing the rest
     831             :  * of the branch, making this function's name somewhat inaccurate.
     832             :  *
     833             :  * Usually, the return value is just "top", but in some cases where we
     834             :  * have parsed the rest of the branch, we may deem "top" redundant and
     835             :  * free it, returning some child subre instead.
     836             :  */
     837             : static struct subre *
     838       94456 : parseqatom(struct vars *v,
     839             :            int stopper,         /* EOS or ')' */
     840             :            int type,            /* LACON (lookaround subRE) or PLAIN */
     841             :            struct state *lp,    /* left state to hang it on */
     842             :            struct state *rp,    /* right state to hang it on */
     843             :            struct subre *top)   /* subtree top */
     844             : {
     845             :     struct state *s;            /* temporaries for new states */
     846             :     struct state *s2;
     847             : 
     848             : #define  ARCV(t, val)    newarc(v->nfa, t, val, lp, rp)
     849             :     int         m,
     850             :                 n;
     851             :     struct subre *atom;         /* atom's subtree */
     852             :     struct subre *t;
     853             :     int         cap;            /* capturing parens? */
     854             :     int         latype;         /* lookaround constraint type */
     855             :     int         subno;          /* capturing-parens or backref number */
     856             :     int         atomtype;
     857             :     int         qprefer;        /* quantifier short/long preference */
     858             :     int         f;
     859             :     struct subre **atomp;       /* where the pointer to atom is */
     860             : 
     861             :     /* initial bookkeeping */
     862       94456 :     atom = NULL;
     863             :     assert(lp->nouts == 0);      /* must string new code */
     864             :     assert(rp->nins == 0);       /* between lp and rp */
     865       94456 :     subno = 0;                  /* just to shut lint up */
     866             : 
     867             :     /* an atom or constraint... */
     868       94456 :     atomtype = v->nexttype;
     869       94456 :     switch (atomtype)
     870             :     {
     871             :             /* first, constraints, which end by returning */
     872        4702 :         case '^':
     873        4702 :             ARCV('^', 1);
     874        4702 :             if (v->cflags & REG_NLANCH)
     875         414 :                 ARCV(BEHIND, v->nlcolor);
     876        4702 :             NEXT();
     877        4702 :             return top;
     878             :             break;
     879        4134 :         case '$':
     880        4134 :             ARCV('$', 1);
     881        4134 :             if (v->cflags & REG_NLANCH)
     882         390 :                 ARCV(AHEAD, v->nlcolor);
     883        4134 :             NEXT();
     884        4134 :             return top;
     885             :             break;
     886          26 :         case SBEGIN:
     887          26 :             ARCV('^', 1);       /* BOL */
     888          26 :             ARCV('^', 0);       /* or BOS */
     889          26 :             NEXT();
     890          26 :             return top;
     891             :             break;
     892          10 :         case SEND:
     893          10 :             ARCV('$', 1);       /* EOL */
     894          10 :             ARCV('$', 0);       /* or EOS */
     895          10 :             NEXT();
     896          10 :             return top;
     897             :             break;
     898          58 :         case '<':
     899          58 :             wordchrs(v);
     900          58 :             s = newstate(v->nfa);
     901          58 :             NOERRN();
     902          58 :             nonword(v, BEHIND, lp, s);
     903          58 :             word(v, AHEAD, s, rp);
     904          58 :             NEXT();
     905          58 :             return top;
     906             :             break;
     907          52 :         case '>':
     908          52 :             wordchrs(v);
     909          52 :             s = newstate(v->nfa);
     910          52 :             NOERRN();
     911          52 :             word(v, BEHIND, lp, s);
     912          52 :             nonword(v, AHEAD, s, rp);
     913          52 :             NEXT();
     914          52 :             return top;
     915             :             break;
     916          18 :         case WBDRY:
     917          18 :             wordchrs(v);
     918          18 :             s = newstate(v->nfa);
     919          18 :             NOERRN();
     920          18 :             nonword(v, BEHIND, lp, s);
     921          18 :             word(v, AHEAD, s, rp);
     922          18 :             s = newstate(v->nfa);
     923          18 :             NOERRN();
     924          18 :             word(v, BEHIND, lp, s);
     925          18 :             nonword(v, AHEAD, s, rp);
     926          18 :             NEXT();
     927          18 :             return top;
     928             :             break;
     929          38 :         case NWBDRY:
     930          38 :             wordchrs(v);
     931          38 :             s = newstate(v->nfa);
     932          38 :             NOERRN();
     933          38 :             word(v, BEHIND, lp, s);
     934          38 :             word(v, AHEAD, s, rp);
     935          38 :             s = newstate(v->nfa);
     936          38 :             NOERRN();
     937          38 :             nonword(v, BEHIND, lp, s);
     938          38 :             nonword(v, AHEAD, s, rp);
     939          38 :             NEXT();
     940          38 :             return top;
     941             :             break;
     942         268 :         case LACON:             /* lookaround constraint */
     943         268 :             latype = v->nextvalue;
     944         268 :             NEXT();
     945         268 :             s = newstate(v->nfa);
     946         268 :             s2 = newstate(v->nfa);
     947         268 :             NOERRN();
     948         268 :             t = parse(v, ')', LACON, s, s2);
     949         268 :             freesubre(v, t);    /* internal structure irrelevant */
     950         268 :             NOERRN();
     951             :             assert(SEE(')'));
     952         254 :             NEXT();
     953         254 :             processlacon(v, s, s2, latype, lp, rp);
     954         254 :             return top;
     955             :             break;
     956             :             /* then errors, to get them out of the way */
     957          68 :         case '*':
     958             :         case '+':
     959             :         case '?':
     960             :         case '{':
     961          68 :             ERR(REG_BADRPT);
     962          68 :             return top;
     963             :             break;
     964           0 :         default:
     965           0 :             ERR(REG_ASSERT);
     966           0 :             return top;
     967             :             break;
     968             :             /* then plain characters, and minor variants on that theme */
     969           6 :         case ')':               /* unbalanced paren */
     970           6 :             if ((v->cflags & REG_ADVANCED) != REG_EXTENDED)
     971             :             {
     972           4 :                 ERR(REG_EPAREN);
     973           4 :                 return top;
     974             :             }
     975             :             /* legal in EREs due to specification botch */
     976           2 :             NOTE(REG_UPBOTCH);
     977             :             /* fall through into case PLAIN */
     978             :             /* FALLTHROUGH */
     979       75130 :         case PLAIN:
     980       75130 :             onechr(v, v->nextvalue, lp, rp);
     981       75130 :             okcolors(v->nfa, v->cm);
     982       75130 :             NOERRN();
     983       75130 :             NEXT();
     984       75130 :             break;
     985        1246 :         case '[':
     986        1246 :             if (v->nextvalue == 1)
     987        1002 :                 bracket(v, lp, rp);
     988             :             else
     989         244 :                 cbracket(v, lp, rp);
     990             :             assert(SEE(']') || ISERR());
     991        1246 :             NEXT();
     992        1246 :             break;
     993         368 :         case CCLASSS:
     994         368 :             charclass(v, (enum char_classes) v->nextvalue, lp, rp);
     995         368 :             okcolors(v->nfa, v->cm);
     996         368 :             NEXT();
     997         368 :             break;
     998          46 :         case CCLASSC:
     999          46 :             charclasscomplement(v, (enum char_classes) v->nextvalue, lp, rp);
    1000             :             /* charclasscomplement() did okcolors() internally */
    1001          46 :             NEXT();
    1002          46 :             break;
    1003        3070 :         case '.':
    1004        3070 :             rainbow(v->nfa, v->cm, PLAIN,
    1005        3070 :                     (v->cflags & REG_NLSTOP) ? v->nlcolor : COLORLESS,
    1006             :                     lp, rp);
    1007        3070 :             NEXT();
    1008        3070 :             break;
    1009             :             /* and finally the ugly stuff */
    1010        4992 :         case '(':               /* value flags as capturing or non */
    1011        4992 :             cap = (type == LACON) ? 0 : v->nextvalue;
    1012        4992 :             if (cap)
    1013             :             {
    1014        4766 :                 v->nsubexp++;
    1015        4766 :                 subno = v->nsubexp;
    1016        4766 :                 if ((size_t) subno >= v->nsubs)
    1017          24 :                     moresubs(v, subno);
    1018             :             }
    1019             :             else
    1020         226 :                 atomtype = PLAIN;   /* something that's not '(' */
    1021        4992 :             NEXT();
    1022             : 
    1023             :             /*
    1024             :              * Make separate endpoint states to keep this sub-NFA distinct
    1025             :              * from what surrounds it.  We need to be sure that when we
    1026             :              * duplicate the sub-NFA for a backref, we get the right
    1027             :              * states/arcs and no others.  In particular, letting a backref
    1028             :              * duplicate the sub-NFA from lp to rp would be quite wrong,
    1029             :              * because we may add quantification superstructure around this
    1030             :              * atom below.  (Perhaps we could skip the extra states for
    1031             :              * non-capturing parens, but it seems not worth the trouble.)
    1032             :              */
    1033        4992 :             s = newstate(v->nfa);
    1034        4992 :             s2 = newstate(v->nfa);
    1035        4992 :             NOERRN();
    1036             :             /* We may not need these arcs, but keep things connected for now */
    1037        4992 :             EMPTYARC(lp, s);
    1038        4992 :             EMPTYARC(s2, rp);
    1039        4992 :             NOERRN();
    1040        4992 :             atom = parse(v, ')', type, s, s2);
    1041             :             assert(SEE(')') || ISERR());
    1042        4992 :             NEXT();
    1043        4992 :             NOERRN();
    1044        4938 :             if (cap)
    1045             :             {
    1046        4720 :                 if (atom->capno == 0)
    1047             :                 {
    1048             :                     /* normal case: just mark the atom as capturing */
    1049        4664 :                     atom->flags |= CAP;
    1050        4664 :                     atom->capno = subno;
    1051             :                 }
    1052             :                 else
    1053             :                 {
    1054             :                     /* generate no-op wrapper node to handle "((x))" */
    1055          56 :                     t = subre(v, '(', atom->flags | CAP, s, s2);
    1056          56 :                     NOERRN();
    1057          56 :                     t->capno = subno;
    1058          56 :                     t->child = atom;
    1059          56 :                     atom = t;
    1060             :                 }
    1061             :                 assert(v->subs[subno] == NULL);
    1062        4720 :                 v->subs[subno] = atom;
    1063             :             }
    1064             :             /* postpone everything else pending possible {0} */
    1065        4938 :             break;
    1066         226 :         case BACKREF:           /* the Feature From The Black Lagoon */
    1067         226 :             INSIST(type != LACON, REG_ESUBREG);
    1068         226 :             subno = v->nextvalue;
    1069             :             assert(subno > 0);
    1070         226 :             INSIST(subno < v->nsubs, REG_ESUBREG);
    1071         226 :             NOERRN();
    1072         212 :             INSIST(v->subs[subno] != NULL, REG_ESUBREG);
    1073         212 :             NOERRN();
    1074         202 :             atom = subre(v, 'b', BACKR, lp, rp);
    1075         202 :             NOERRN();
    1076         202 :             atom->backno = subno;
    1077         202 :             v->subs[subno]->flags |= BRUSE;
    1078         202 :             EMPTYARC(lp, rp);   /* temporarily, so there's something */
    1079         202 :             NEXT();
    1080         202 :             break;
    1081             :     }
    1082             : 
    1083             :     /* ...and an atom may be followed by a quantifier */
    1084       85000 :     switch (v->nexttype)
    1085             :     {
    1086       21142 :         case '*':
    1087       21142 :             m = 0;
    1088       21142 :             n = DUPINF;
    1089       21142 :             qprefer = (v->nextvalue) ? LONGER : SHORTER;
    1090       21142 :             NEXT();
    1091       21142 :             break;
    1092         902 :         case '+':
    1093         902 :             m = 1;
    1094         902 :             n = DUPINF;
    1095         902 :             qprefer = (v->nextvalue) ? LONGER : SHORTER;
    1096         902 :             NEXT();
    1097         902 :             break;
    1098         116 :         case '?':
    1099         116 :             m = 0;
    1100         116 :             n = 1;
    1101         116 :             qprefer = (v->nextvalue) ? LONGER : SHORTER;
    1102         116 :             NEXT();
    1103         116 :             break;
    1104         522 :         case '{':
    1105         522 :             NEXT();
    1106         522 :             m = scannum(v);
    1107         522 :             if (EAT(','))
    1108             :             {
    1109         242 :                 if (SEE(DIGIT))
    1110         228 :                     n = scannum(v);
    1111             :                 else
    1112          14 :                     n = DUPINF;
    1113         242 :                 if (m > n)
    1114             :                 {
    1115           8 :                     ERR(REG_BADBR);
    1116           8 :                     return top;
    1117             :                 }
    1118             :                 /* {m,n} exercises preference, even if it's {m,m} */
    1119         234 :                 qprefer = (v->nextvalue) ? LONGER : SHORTER;
    1120             :             }
    1121             :             else
    1122             :             {
    1123         280 :                 n = m;
    1124             :                 /* {m} passes operand's preference through */
    1125         280 :                 qprefer = 0;
    1126             :             }
    1127         514 :             if (!SEE('}'))
    1128             :             {                   /* catches errors too */
    1129          14 :                 ERR(REG_BADBR);
    1130          14 :                 return top;
    1131             :             }
    1132         500 :             NEXT();
    1133         500 :             break;
    1134       62318 :         default:                /* no quantifier */
    1135       62318 :             m = n = 1;
    1136       62318 :             qprefer = 0;
    1137       62318 :             break;
    1138             :     }
    1139             : 
    1140             :     /* annoying special case:  {0} or {0,0} cancels everything */
    1141       84978 :     if (m == 0 && n == 0)
    1142             :     {
    1143             :         /*
    1144             :          * If we had capturing subexpression(s) within the atom, we don't want
    1145             :          * to destroy them, because it's legal (if useless) to back-ref them
    1146             :          * later.  Hence, just unlink the atom from lp/rp and then ignore it.
    1147             :          */
    1148          42 :         if (atom != NULL && (atom->flags & CAP))
    1149             :         {
    1150          36 :             delsub(v->nfa, lp, atom->begin);
    1151          36 :             delsub(v->nfa, atom->end, rp);
    1152             :         }
    1153             :         else
    1154             :         {
    1155             :             /* Otherwise, we can clean up any subre infrastructure we made */
    1156           6 :             if (atom != NULL)
    1157           2 :                 freesubre(v, atom);
    1158           6 :             delsub(v->nfa, lp, rp);
    1159             :         }
    1160          42 :         EMPTYARC(lp, rp);
    1161          42 :         return top;
    1162             :     }
    1163             : 
    1164             :     /* if not a messy case, avoid hard part */
    1165             :     assert(!MESSY(top->flags));
    1166       84936 :     f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0);
    1167       84936 :     if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f)))
    1168             :     {
    1169       80018 :         if (!(m == 1 && n == 1))
    1170       21952 :             repeat(v, lp, rp, m, n);
    1171       80018 :         if (atom != NULL)
    1172         180 :             freesubre(v, atom);
    1173       80018 :         top->flags = f;
    1174       80018 :         return top;
    1175             :     }
    1176             : 
    1177             :     /*
    1178             :      * hard part:  something messy
    1179             :      *
    1180             :      * That is, capturing parens, back reference, short/long clash, or an atom
    1181             :      * with substructure containing one of those.
    1182             :      */
    1183             : 
    1184             :     /* now we'll need a subre for the contents even if they're boring */
    1185        4918 :     if (atom == NULL)
    1186             :     {
    1187           2 :         atom = subre(v, '=', 0, lp, rp);
    1188           2 :         NOERRN();
    1189             :     }
    1190             : 
    1191             :     /*
    1192             :      * For what follows, we need the atom to have its own begin/end states
    1193             :      * that are distinct from lp/rp, so that we can wrap iteration structure
    1194             :      * around it.  The parenthesized-atom case above already made suitable
    1195             :      * states (and we don't want to modify a capturing subre, since it's
    1196             :      * already recorded in v->subs[]).  Otherwise, we need more states.
    1197             :      */
    1198        4918 :     if (atom->begin == lp || atom->end == rp)
    1199             :     {
    1200         204 :         s = newstate(v->nfa);
    1201         204 :         s2 = newstate(v->nfa);
    1202         204 :         NOERRN();
    1203         204 :         moveouts(v->nfa, lp, s);
    1204         204 :         moveins(v->nfa, rp, s2);
    1205         204 :         atom->begin = s;
    1206         204 :         atom->end = s2;
    1207             :     }
    1208             :     else
    1209             :     {
    1210             :         /* The atom's OK, but we must temporarily disconnect it from lp/rp */
    1211             :         /* (this removes the EMPTY arcs we made above) */
    1212        4714 :         delsub(v->nfa, lp, atom->begin);
    1213        4714 :         delsub(v->nfa, atom->end, rp);
    1214             :     }
    1215             : 
    1216             :     /*----------
    1217             :      * Prepare a general-purpose state skeleton.
    1218             :      *
    1219             :      * In the no-backrefs case, we want this:
    1220             :      *
    1221             :      * [lp] ---> [s] ---prefix---> ---atom---> ---rest---> [rp]
    1222             :      *
    1223             :      * where prefix is some repetitions of atom, and "rest" is the remainder
    1224             :      * of the branch.  In the general case we need:
    1225             :      *
    1226             :      * [lp] ---> [s] ---iterator---> [s2] ---rest---> [rp]
    1227             :      *
    1228             :      * where the iterator wraps around the atom.
    1229             :      *
    1230             :      * We make the s state here for both cases; s2 is made below if needed
    1231             :      *----------
    1232             :      */
    1233        4918 :     s = newstate(v->nfa);        /* set up starting state */
    1234        4918 :     NOERRN();
    1235        4918 :     EMPTYARC(lp, s);
    1236        4918 :     NOERRN();
    1237             : 
    1238             :     /* break remaining subRE into x{...} and what follows */
    1239        4918 :     t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp);
    1240        4918 :     NOERRN();
    1241        4918 :     t->child = atom;
    1242        4918 :     atomp = &t->child;
    1243             : 
    1244             :     /*
    1245             :      * Here we should recurse to fill t->child->sibling ... but we must
    1246             :      * postpone that to the end.  One reason is that t->child may be replaced
    1247             :      * below, and we don't want to worry about its sibling link.
    1248             :      */
    1249             : 
    1250             :     /*
    1251             :      * Convert top node to a concatenation of the prefix (top->child, covering
    1252             :      * whatever we parsed previously) and remaining (t).  Note that the prefix
    1253             :      * could be empty, in which case this concatenation node is unnecessary.
    1254             :      * To keep things simple, we operate in a general way for now, and get rid
    1255             :      * of unnecessary subres below.
    1256             :      */
    1257             :     assert(top->op == '=' && top->child == NULL);
    1258        4918 :     top->child = subre(v, '=', top->flags, top->begin, lp);
    1259        4918 :     NOERRN();
    1260        4918 :     top->op = '.';
    1261        4918 :     top->child->sibling = t;
    1262             :     /* top->flags will get updated later */
    1263             : 
    1264             :     /* if it's a backref, now is the time to replicate the subNFA */
    1265        4918 :     if (atomtype == BACKREF)
    1266             :     {
    1267             :         assert(atom->begin->nouts == 1);  /* just the EMPTY */
    1268         202 :         delsub(v->nfa, atom->begin, atom->end);
    1269             :         assert(v->subs[subno] != NULL);
    1270             : 
    1271             :         /*
    1272             :          * And here's why the recursion got postponed: it must wait until the
    1273             :          * skeleton is filled in, because it may hit a backref that wants to
    1274             :          * copy the filled-in skeleton.
    1275             :          */
    1276         202 :         dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end,
    1277             :                atom->begin, atom->end);
    1278         202 :         NOERRN();
    1279             : 
    1280             :         /* The backref node's NFA should not enforce any constraints */
    1281         202 :         removeconstraints(v->nfa, atom->begin, atom->end);
    1282         202 :         NOERRN();
    1283             :     }
    1284             : 
    1285             :     /*
    1286             :      * It's quantifier time.  If the atom is just a backref, we'll let it deal
    1287             :      * with quantifiers internally.
    1288             :      */
    1289        4918 :     if (atomtype == BACKREF)
    1290             :     {
    1291             :         /* special case:  backrefs have internal quantifiers */
    1292         202 :         EMPTYARC(s, atom->begin);    /* empty prefix */
    1293             :         /* just stuff everything into atom */
    1294         202 :         repeat(v, atom->begin, atom->end, m, n);
    1295         202 :         atom->min = (short) m;
    1296         202 :         atom->max = (short) n;
    1297         202 :         atom->flags |= COMBINE(qprefer, atom->flags);
    1298             :         /* rest of branch can be strung starting from atom->end */
    1299         202 :         s2 = atom->end;
    1300             :     }
    1301        4716 :     else if (m == 1 && n == 1 &&
    1302         106 :              (qprefer == 0 ||
    1303         106 :               (atom->flags & (LONGER | SHORTER | MIXED)) == 0 ||
    1304          92 :               qprefer == (atom->flags & (LONGER | SHORTER | MIXED))))
    1305             :     {
    1306             :         /* no/vacuous quantifier:  done */
    1307        4272 :         EMPTYARC(s, atom->begin);    /* empty prefix */
    1308             :         /* rest of branch can be strung starting from atom->end */
    1309        4272 :         s2 = atom->end;
    1310             :     }
    1311         444 :     else if (!(atom->flags & (CAP | BACKR)))
    1312             :     {
    1313             :         /*
    1314             :          * If there's no captures nor backrefs in the atom being repeated, we
    1315             :          * don't really care where the submatches of the iteration are, so we
    1316             :          * don't need an iteration node.  Make a plain DFA node instead.
    1317             :          */
    1318          16 :         EMPTYARC(s, atom->begin);    /* empty prefix */
    1319          16 :         repeat(v, atom->begin, atom->end, m, n);
    1320          16 :         f = COMBINE(qprefer, atom->flags);
    1321          16 :         t = subre(v, '=', f, atom->begin, atom->end);
    1322          16 :         NOERRN();
    1323          16 :         freesubre(v, atom);
    1324          16 :         *atomp = t;
    1325             :         /* rest of branch can be strung starting from t->end */
    1326          16 :         s2 = t->end;
    1327             :     }
    1328         428 :     else if (m > 0 && !(atom->flags & BACKR))
    1329             :     {
    1330             :         /*
    1331             :          * If there's no backrefs involved, we can turn x{m,n} into
    1332             :          * x{m-1,n-1}x, with capturing parens in only the second x.  This is
    1333             :          * valid because we only care about capturing matches from the final
    1334             :          * iteration of the quantifier.  It's a win because we can implement
    1335             :          * the backref-free left side as a plain DFA node, since we don't
    1336             :          * really care where its submatches are.
    1337             :          */
    1338         268 :         dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin);
    1339             :         assert(m >= 1 && m != DUPINF && n >= 1);
    1340         268 :         repeat(v, s, atom->begin, m - 1, (n == DUPINF) ? n : n - 1);
    1341         268 :         f = COMBINE(qprefer, atom->flags);
    1342         268 :         t = subre(v, '.', f, s, atom->end); /* prefix and atom */
    1343         268 :         NOERRN();
    1344         268 :         t->child = subre(v, '=', PREF(f), s, atom->begin);
    1345         268 :         NOERRN();
    1346         268 :         t->child->sibling = atom;
    1347         268 :         *atomp = t;
    1348             :         /* rest of branch can be strung starting from atom->end */
    1349         268 :         s2 = atom->end;
    1350             :     }
    1351             :     else
    1352             :     {
    1353             :         /* general case: need an iteration node */
    1354         160 :         s2 = newstate(v->nfa);
    1355         160 :         NOERRN();
    1356         160 :         moveouts(v->nfa, atom->end, s2);
    1357         160 :         NOERRN();
    1358         160 :         dupnfa(v->nfa, atom->begin, atom->end, s, s2);
    1359         160 :         repeat(v, s, s2, m, n);
    1360         160 :         f = COMBINE(qprefer, atom->flags);
    1361         160 :         t = subre(v, '*', f, s, s2);
    1362         160 :         NOERRN();
    1363         160 :         t->min = (short) m;
    1364         160 :         t->max = (short) n;
    1365         160 :         t->child = atom;
    1366         160 :         *atomp = t;
    1367             :         /* rest of branch is to be strung from iteration's end state */
    1368             :     }
    1369             : 
    1370             :     /* and finally, look after that postponed recursion */
    1371        4918 :     t = top->child->sibling;
    1372        4918 :     if (!(SEE('|') || SEE(stopper) || SEE(EOS)))
    1373             :     {
    1374             :         /* parse all the rest of the branch, and insert in t->child->sibling */
    1375        4194 :         t->child->sibling = parsebranch(v, stopper, type, s2, rp, 1);
    1376        4194 :         NOERRN();
    1377             :         assert(SEE('|') || SEE(stopper) || SEE(EOS));
    1378             : 
    1379             :         /* here's the promised update of the flags */
    1380        4170 :         t->flags |= COMBINE(t->flags, t->child->sibling->flags);
    1381        4170 :         top->flags |= COMBINE(top->flags, t->flags);
    1382             : 
    1383             :         /* neither t nor top could be directly marked for capture as yet */
    1384             :         assert(t->capno == 0);
    1385             :         assert(top->capno == 0);
    1386             : 
    1387             :         /*
    1388             :          * At this point both top and t are concatenation (op == '.') subres,
    1389             :          * and we have top->child = prefix of branch, top->child->sibling = t,
    1390             :          * t->child = messy atom (with quantification superstructure if
    1391             :          * needed), t->child->sibling = rest of branch.
    1392             :          *
    1393             :          * If the messy atom was the first thing in the branch, then
    1394             :          * top->child is vacuous and we can get rid of one level of
    1395             :          * concatenation.
    1396             :          */
    1397             :         assert(top->child->op == '=');
    1398        4170 :         if (top->child->begin == top->child->end)
    1399             :         {
    1400             :             assert(!MESSY(top->child->flags));
    1401         666 :             freesubre(v, top->child);
    1402         666 :             top->child = t->child;
    1403         666 :             freesrnode(v, t);
    1404             :         }
    1405             : 
    1406             :         /*
    1407             :          * Otherwise, it's possible that t->child is not messy in itself, but
    1408             :          * we considered it messy because its greediness conflicts with what
    1409             :          * preceded it.  Then it could be that the combination of t->child and
    1410             :          * the rest of the branch is also not messy, in which case we can get
    1411             :          * rid of the child concatenation by merging t->child and the rest of
    1412             :          * the branch into one plain DFA node.
    1413             :          */
    1414        3504 :         else if (t->child->op == '=' &&
    1415        3402 :                  t->child->sibling->op == '=' &&
    1416        3206 :                  !MESSY(UP(t->child->flags | t->child->sibling->flags)))
    1417             :         {
    1418           0 :             t->op = '=';
    1419           0 :             t->flags = COMBINE(t->child->flags, t->child->sibling->flags);
    1420           0 :             freesubreandsiblings(v, t->child);
    1421           0 :             t->child = NULL;
    1422             :         }
    1423             :     }
    1424             :     else
    1425             :     {
    1426             :         /*
    1427             :          * There's nothing left in the branch, so we don't need the second
    1428             :          * concatenation node 't'.  Just link s2 straight to rp.
    1429             :          */
    1430         724 :         EMPTYARC(s2, rp);
    1431         724 :         top->child->sibling = t->child;
    1432         724 :         top->flags |= COMBINE(top->flags, top->child->sibling->flags);
    1433         724 :         freesrnode(v, t);
    1434             : 
    1435             :         /*
    1436             :          * Again, it could be that top->child is vacuous (if the messy atom
    1437             :          * was in fact the only thing in the branch).  In that case we need no
    1438             :          * concatenation at all; just replace top with top->child->sibling.
    1439             :          */
    1440             :         assert(top->child->op == '=');
    1441         724 :         if (top->child->begin == top->child->end)
    1442             :         {
    1443             :             assert(!MESSY(top->child->flags));
    1444         520 :             t = top->child->sibling;
    1445         520 :             top->child->sibling = NULL;
    1446         520 :             freesubre(v, top);
    1447         520 :             top = t;
    1448             :         }
    1449             :     }
    1450             : 
    1451        4894 :     return top;
    1452             : }
    1453             : 
    1454             : /*
    1455             :  * nonword - generate arcs for non-word-character ahead or behind
    1456             :  */
    1457             : static void
    1458         222 : nonword(struct vars *v,
    1459             :         int dir,                /* AHEAD or BEHIND */
    1460             :         struct state *lp,
    1461             :         struct state *rp)
    1462             : {
    1463         222 :     int         anchor = (dir == AHEAD) ? '$' : '^';
    1464             : 
    1465             :     assert(dir == AHEAD || dir == BEHIND);
    1466         222 :     newarc(v->nfa, anchor, 1, lp, rp);
    1467         222 :     newarc(v->nfa, anchor, 0, lp, rp);
    1468         222 :     colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp);
    1469             :     /* (no need for special attention to \n) */
    1470         222 : }
    1471             : 
    1472             : /*
    1473             :  * word - generate arcs for word character ahead or behind
    1474             :  */
    1475             : static void
    1476         222 : word(struct vars *v,
    1477             :      int dir,                   /* AHEAD or BEHIND */
    1478             :      struct state *lp,
    1479             :      struct state *rp)
    1480             : {
    1481             :     assert(dir == AHEAD || dir == BEHIND);
    1482         222 :     cloneouts(v->nfa, v->wordchrs, lp, rp, dir);
    1483             :     /* (no need for special attention to \n) */
    1484         222 : }
    1485             : 
    1486             : /*
    1487             :  * charclass - generate arcs for a character class
    1488             :  *
    1489             :  * This is used for both atoms (\w and sibling escapes) and for elements
    1490             :  * of bracket expressions.  The caller is responsible for calling okcolors()
    1491             :  * at the end of processing the atom or bracket.
    1492             :  */
    1493             : static void
    1494         624 : charclass(struct vars *v,
    1495             :           enum char_classes cls,
    1496             :           struct state *lp,
    1497             :           struct state *rp)
    1498             : {
    1499             :     struct cvec *cv;
    1500             : 
    1501             :     /* obtain possibly-cached cvec for char class */
    1502         624 :     NOTE(REG_ULOCALE);
    1503         624 :     cv = cclasscvec(v, cls, (v->cflags & REG_ICASE));
    1504         624 :     NOERR();
    1505             : 
    1506             :     /* build the arcs; this may cause color splitting */
    1507         624 :     subcolorcvec(v, cv, lp, rp);
    1508             : }
    1509             : 
    1510             : /*
    1511             :  * charclasscomplement - generate arcs for a complemented character class
    1512             :  *
    1513             :  * This is used for both atoms (\W and sibling escapes) and for elements
    1514             :  * of bracket expressions.  In bracket expressions, it is the caller's
    1515             :  * responsibility that there not be any open subcolors when this is called.
    1516             :  */
    1517             : static void
    1518          78 : charclasscomplement(struct vars *v,
    1519             :                     enum char_classes cls,
    1520             :                     struct state *lp,
    1521             :                     struct state *rp)
    1522             : {
    1523             :     struct state *cstate;
    1524             :     struct cvec *cv;
    1525             : 
    1526             :     /* make dummy state to hang temporary arcs on */
    1527          78 :     cstate = newstate(v->nfa);
    1528          78 :     NOERR();
    1529             : 
    1530             :     /* obtain possibly-cached cvec for char class */
    1531          78 :     NOTE(REG_ULOCALE);
    1532          78 :     cv = cclasscvec(v, cls, (v->cflags & REG_ICASE));
    1533          78 :     NOERR();
    1534             : 
    1535             :     /* build arcs for char class; this may cause color splitting */
    1536          78 :     subcolorcvec(v, cv, cstate, cstate);
    1537          78 :     NOERR();
    1538             : 
    1539             :     /* clean up any subcolors in the arc set */
    1540          78 :     okcolors(v->nfa, v->cm);
    1541          78 :     NOERR();
    1542             : 
    1543             :     /* now build output arcs for the complement of the char class */
    1544          78 :     colorcomplement(v->nfa, v->cm, PLAIN, cstate, lp, rp);
    1545          78 :     NOERR();
    1546             : 
    1547             :     /* clean up dummy state */
    1548          78 :     dropstate(v->nfa, cstate);
    1549             : }
    1550             : 
    1551             : /*
    1552             :  * scannum - scan a number
    1553             :  */
    1554             : static int                      /* value, <= DUPMAX */
    1555         750 : scannum(struct vars *v)
    1556             : {
    1557         750 :     int         n = 0;
    1558             : 
    1559        1584 :     while (SEE(DIGIT) && n < DUPMAX)
    1560             :     {
    1561         834 :         n = n * 10 + v->nextvalue;
    1562         834 :         NEXT();
    1563             :     }
    1564         750 :     if (SEE(DIGIT) || n > DUPMAX)
    1565             :     {
    1566           4 :         ERR(REG_BADBR);
    1567           4 :         return 0;
    1568             :     }
    1569         746 :     return n;
    1570             : }
    1571             : 
    1572             : /*
    1573             :  * repeat - replicate subNFA for quantifiers
    1574             :  *
    1575             :  * The sub-NFA strung from lp to rp is modified to represent m to n
    1576             :  * repetitions of its initial contents.
    1577             :  *
    1578             :  * The duplication sequences used here are chosen carefully so that any
    1579             :  * pointers starting out pointing into the subexpression end up pointing into
    1580             :  * the last occurrence.  (Note that it may not be strung between the same
    1581             :  * left and right end states, however!)  This used to be important for the
    1582             :  * subRE tree, although the important bits are now handled by the in-line
    1583             :  * code in parse(), and when this is called, it doesn't matter any more.
    1584             :  */
    1585             : static void
    1586       25088 : repeat(struct vars *v,
    1587             :        struct state *lp,
    1588             :        struct state *rp,
    1589             :        int m,
    1590             :        int n)
    1591             : {
    1592             : #define  SOME    2
    1593             : #define  INF     3
    1594             : #define  PAIR(x, y)  ((x)*4 + (y))
    1595             : #define  REDUCE(x)   ( ((x) == DUPINF) ? INF : (((x) > 1) ? SOME : (x)) )
    1596       25088 :     const int   rm = REDUCE(m);
    1597       25088 :     const int   rn = REDUCE(n);
    1598             :     struct state *s;
    1599             :     struct state *s2;
    1600             : 
    1601       25088 :     switch (PAIR(rm, rn))
    1602             :     {
    1603          30 :         case PAIR(0, 0):        /* empty string */
    1604          30 :             delsub(v->nfa, lp, rp);
    1605          30 :             EMPTYARC(lp, rp);
    1606          30 :             break;
    1607         124 :         case PAIR(0, 1):        /* do as x| */
    1608         124 :             EMPTYARC(lp, rp);
    1609         124 :             break;
    1610           4 :         case PAIR(0, SOME):     /* do as x{1,n}| */
    1611           4 :             repeat(v, lp, rp, 1, n);
    1612           4 :             NOERR();
    1613           4 :             EMPTYARC(lp, rp);
    1614           4 :             break;
    1615       21368 :         case PAIR(0, INF):      /* loop x around */
    1616       21368 :             s = newstate(v->nfa);
    1617       21368 :             NOERR();
    1618       21368 :             moveouts(v->nfa, lp, s);
    1619       21368 :             moveins(v->nfa, rp, s);
    1620       21368 :             EMPTYARC(lp, s);
    1621       21368 :             EMPTYARC(s, rp);
    1622       21368 :             break;
    1623         386 :         case PAIR(1, 1):        /* no action required */
    1624         386 :             break;
    1625         698 :         case PAIR(1, SOME):     /* do as x{0,n-1}x = (x{1,n-1}|)x */
    1626         698 :             s = newstate(v->nfa);
    1627         698 :             NOERR();
    1628         698 :             moveouts(v->nfa, lp, s);
    1629         698 :             dupnfa(v->nfa, s, rp, lp, s);
    1630         698 :             NOERR();
    1631         698 :             repeat(v, lp, s, 1, n - 1);
    1632         698 :             NOERR();
    1633         698 :             EMPTYARC(lp, s);
    1634         698 :             break;
    1635         690 :         case PAIR(1, INF):      /* add loopback arc */
    1636         690 :             s = newstate(v->nfa);
    1637         690 :             s2 = newstate(v->nfa);
    1638         690 :             NOERR();
    1639         690 :             moveouts(v->nfa, lp, s);
    1640         690 :             moveins(v->nfa, rp, s2);
    1641         690 :             EMPTYARC(lp, s);
    1642         690 :             EMPTYARC(s2, rp);
    1643         690 :             EMPTYARC(s2, s);
    1644         690 :             break;
    1645        1580 :         case PAIR(SOME, SOME):  /* do as x{m-1,n-1}x */
    1646        1580 :             s = newstate(v->nfa);
    1647        1580 :             NOERR();
    1648        1580 :             moveouts(v->nfa, lp, s);
    1649        1580 :             dupnfa(v->nfa, s, rp, lp, s);
    1650        1580 :             NOERR();
    1651        1580 :             repeat(v, lp, s, m - 1, n - 1);
    1652        1580 :             break;
    1653         208 :         case PAIR(SOME, INF):   /* do as x{m-1,}x */
    1654         208 :             s = newstate(v->nfa);
    1655         208 :             NOERR();
    1656         208 :             moveouts(v->nfa, lp, s);
    1657         208 :             dupnfa(v->nfa, s, rp, lp, s);
    1658         208 :             NOERR();
    1659         208 :             repeat(v, lp, s, m - 1, n);
    1660         208 :             break;
    1661           0 :         default:
    1662           0 :             ERR(REG_ASSERT);
    1663           0 :             break;
    1664             :     }
    1665             : }
    1666             : 
    1667             : /*
    1668             :  * bracket - handle non-complemented bracket expression
    1669             :  *
    1670             :  * Also called from cbracket for complemented bracket expressions.
    1671             :  */
    1672             : static void
    1673        1246 : bracket(struct vars *v,
    1674             :         struct state *lp,
    1675             :         struct state *rp)
    1676             : {
    1677             :     /*
    1678             :      * We can't process complemented char classes (e.g. \W) immediately while
    1679             :      * scanning the bracket expression, else color bookkeeping gets confused.
    1680             :      * Instead, remember whether we saw any in have_cclassc[], and process
    1681             :      * them at the end.
    1682             :      */
    1683             :     bool        have_cclassc[NUM_CCLASSES];
    1684             :     bool        any_cclassc;
    1685             :     int         i;
    1686             : 
    1687        1246 :     memset(have_cclassc, false, sizeof(have_cclassc));
    1688             : 
    1689             :     assert(SEE('['));
    1690        1246 :     NEXT();
    1691        3146 :     while (!SEE(']') && !SEE(EOS))
    1692        1900 :         brackpart(v, lp, rp, have_cclassc);
    1693             :     assert(SEE(']') || ISERR());
    1694             : 
    1695             :     /* close up open subcolors from the positive bracket elements */
    1696        1246 :     okcolors(v->nfa, v->cm);
    1697        1246 :     NOERR();
    1698             : 
    1699             :     /* now handle any complemented elements */
    1700        1176 :     any_cclassc = false;
    1701       17640 :     for (i = 0; i < NUM_CCLASSES; i++)
    1702             :     {
    1703       16464 :         if (have_cclassc[i])
    1704             :         {
    1705          32 :             charclasscomplement(v, (enum char_classes) i, lp, rp);
    1706          32 :             NOERR();
    1707          32 :             any_cclassc = true;
    1708             :         }
    1709             :     }
    1710             : 
    1711             :     /*
    1712             :      * If we had any complemented elements, see if we can optimize the bracket
    1713             :      * into a rainbow.  Since a complemented element is the only way a WHITE
    1714             :      * arc could get into the result, there's no point in checking otherwise.
    1715             :      */
    1716        1176 :     if (any_cclassc)
    1717          32 :         optimizebracket(v, lp, rp);
    1718             : }
    1719             : 
    1720             : /*
    1721             :  * cbracket - handle complemented bracket expression
    1722             :  *
    1723             :  * We do it by calling bracket() with dummy endpoints, and then complementing
    1724             :  * the result.  The alternative would be to invoke rainbow(), and then delete
    1725             :  * arcs as the b.e. is seen... but that gets messy, and is really quite
    1726             :  * infeasible now that rainbow() just puts out one RAINBOW arc.
    1727             :  */
    1728             : static void
    1729         244 : cbracket(struct vars *v,
    1730             :          struct state *lp,
    1731             :          struct state *rp)
    1732             : {
    1733         244 :     struct state *left = newstate(v->nfa);
    1734         244 :     struct state *right = newstate(v->nfa);
    1735             : 
    1736         244 :     NOERR();
    1737         244 :     bracket(v, left, right);
    1738             : 
    1739             :     /* in NLSTOP mode, ensure newline is not part of the result set */
    1740         244 :     if (v->cflags & REG_NLSTOP)
    1741           4 :         newarc(v->nfa, PLAIN, v->nlcolor, left, right);
    1742         244 :     NOERR();
    1743             : 
    1744             :     assert(lp->nouts == 0);      /* all outarcs will be ours */
    1745             : 
    1746             :     /*
    1747             :      * Easy part of complementing, and all there is to do since the MCCE code
    1748             :      * was removed.  Note that the result of colorcomplement() cannot be a
    1749             :      * rainbow, since we don't allow empty brackets; so there's no point in
    1750             :      * calling optimizebracket() again.
    1751             :      */
    1752         244 :     colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
    1753         244 :     NOERR();
    1754         244 :     dropstate(v->nfa, left);
    1755             :     assert(right->nins == 0);
    1756         244 :     freestate(v->nfa, right);
    1757             : }
    1758             : 
    1759             : /*
    1760             :  * brackpart - handle one item (or range) within a bracket expression
    1761             :  */
    1762             : static void
    1763        1900 : brackpart(struct vars *v,
    1764             :           struct state *lp,
    1765             :           struct state *rp,
    1766             :           bool *have_cclassc)
    1767             : {
    1768             :     chr         startc;
    1769             :     chr         endc;
    1770             :     struct cvec *cv;
    1771             :     enum char_classes cls;
    1772             :     const chr  *startp;
    1773             :     const chr  *endp;
    1774             : 
    1775             :     /* parse something, get rid of special cases, take shortcuts */
    1776        1900 :     switch (v->nexttype)
    1777             :     {
    1778           8 :         case RANGE:             /* a-b-c or other botch */
    1779           8 :             ERR(REG_ERANGE);
    1780           8 :             return;
    1781             :             break;
    1782        1544 :         case PLAIN:
    1783        1544 :             startc = v->nextvalue;
    1784        1544 :             NEXT();
    1785             :             /* shortcut for ordinary chr (not range) */
    1786        1544 :             if (!SEE(RANGE))
    1787             :             {
    1788         966 :                 onechr(v, startc, lp, rp);
    1789         966 :                 return;
    1790             :             }
    1791         578 :             NOERR();
    1792         578 :             break;
    1793          20 :         case COLLEL:
    1794          20 :             startp = v->now;
    1795          20 :             endp = scanplain(v);
    1796          20 :             INSIST(startp < endp, REG_ECOLLATE);
    1797          20 :             NOERR();
    1798          16 :             startc = element(v, startp, endp);
    1799          16 :             NOERR();
    1800          12 :             break;
    1801          28 :         case ECLASS:
    1802          28 :             startp = v->now;
    1803          28 :             endp = scanplain(v);
    1804          28 :             INSIST(startp < endp, REG_ECOLLATE);
    1805          28 :             NOERR();
    1806          24 :             startc = element(v, startp, endp);
    1807          24 :             NOERR();
    1808          20 :             cv = eclass(v, startc, (v->cflags & REG_ICASE));
    1809          20 :             NOERR();
    1810          20 :             subcolorcvec(v, cv, lp, rp);
    1811          20 :             return;
    1812             :             break;
    1813         242 :         case CCLASS:
    1814         242 :             startp = v->now;
    1815         242 :             endp = scanplain(v);
    1816         242 :             INSIST(startp < endp, REG_ECTYPE);
    1817         242 :             NOERR();
    1818         238 :             cls = lookupcclass(v, startp, endp);
    1819         238 :             NOERR();
    1820         230 :             charclass(v, cls, lp, rp);
    1821         230 :             return;
    1822             :             break;
    1823          26 :         case CCLASSS:
    1824          26 :             charclass(v, (enum char_classes) v->nextvalue, lp, rp);
    1825          26 :             NEXT();
    1826          26 :             return;
    1827             :             break;
    1828          32 :         case CCLASSC:
    1829             :             /* we cannot call charclasscomplement() immediately */
    1830          32 :             have_cclassc[v->nextvalue] = true;
    1831          32 :             NEXT();
    1832          32 :             return;
    1833             :             break;
    1834           0 :         default:
    1835           0 :             ERR(REG_ASSERT);
    1836           0 :             return;
    1837             :             break;
    1838             :     }
    1839             : 
    1840         590 :     if (SEE(RANGE))
    1841             :     {
    1842         582 :         NEXT();
    1843         582 :         switch (v->nexttype)
    1844             :         {
    1845         562 :             case PLAIN:
    1846             :             case RANGE:
    1847         562 :                 endc = v->nextvalue;
    1848         562 :                 NEXT();
    1849         562 :                 NOERR();
    1850         558 :                 break;
    1851           4 :             case COLLEL:
    1852           4 :                 startp = v->now;
    1853           4 :                 endp = scanplain(v);
    1854           4 :                 INSIST(startp < endp, REG_ECOLLATE);
    1855           4 :                 NOERR();
    1856           4 :                 endc = element(v, startp, endp);
    1857           4 :                 NOERR();
    1858           4 :                 break;
    1859          16 :             default:
    1860          16 :                 ERR(REG_ERANGE);
    1861          16 :                 return;
    1862             :                 break;
    1863             :         }
    1864             :     }
    1865             :     else
    1866           8 :         endc = startc;
    1867             : 
    1868             :     /*
    1869             :      * Ranges are unportable.  Actually, standard C does guarantee that digits
    1870             :      * are contiguous, but making that an exception is just too complicated.
    1871             :      */
    1872         570 :     if (startc != endc)
    1873         554 :         NOTE(REG_UUNPORT);
    1874         570 :     cv = range(v, startc, endc, (v->cflags & REG_ICASE));
    1875         570 :     NOERR();
    1876         566 :     subcolorcvec(v, cv, lp, rp);
    1877             : }
    1878             : 
    1879             : /*
    1880             :  * scanplain - scan PLAIN contents of [. etc.
    1881             :  *
    1882             :  * Certain bits of trickery in regc_lex.c know that this code does not try
    1883             :  * to look past the final bracket of the [. etc.
    1884             :  */
    1885             : static const chr *              /* just after end of sequence */
    1886         294 : scanplain(struct vars *v)
    1887             : {
    1888             :     const chr  *endp;
    1889             : 
    1890             :     assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
    1891         294 :     NEXT();
    1892             : 
    1893         294 :     endp = v->now;
    1894        1546 :     while (SEE(PLAIN))
    1895             :     {
    1896        1252 :         endp = v->now;
    1897        1252 :         NEXT();
    1898             :     }
    1899             : 
    1900             :     assert(SEE(END) || ISERR());
    1901         294 :     NEXT();
    1902             : 
    1903         294 :     return endp;
    1904             : }
    1905             : 
    1906             : /*
    1907             :  * onechr - fill in arcs for a plain character, and possible case complements
    1908             :  * This is mostly a shortcut for efficient handling of the common case.
    1909             :  */
    1910             : static void
    1911       76096 : onechr(struct vars *v,
    1912             :        chr c,
    1913             :        struct state *lp,
    1914             :        struct state *rp)
    1915             : {
    1916       76096 :     if (!(v->cflags & REG_ICASE))
    1917             :     {
    1918       74474 :         color       lastsubcolor = COLORLESS;
    1919             : 
    1920       74474 :         subcoloronechr(v, c, lp, rp, &lastsubcolor);
    1921       74474 :         return;
    1922             :     }
    1923             : 
    1924             :     /* rats, need general case anyway... */
    1925        1622 :     subcolorcvec(v, allcases(v, c), lp, rp);
    1926             : }
    1927             : 
    1928             : /*
    1929             :  * optimizebracket - see if bracket expression can be converted to RAINBOW
    1930             :  *
    1931             :  * Cases such as "[\s\S]" can produce a set of arcs of all colors, which we
    1932             :  * can replace by a single RAINBOW arc for efficiency.  (This might seem
    1933             :  * like a silly way to write ".", but it's seemingly a common locution in
    1934             :  * some other flavors of regex, so take the trouble to support it well.)
    1935             :  */
    1936             : static void
    1937          32 : optimizebracket(struct vars *v,
    1938             :                 struct state *lp,
    1939             :                 struct state *rp)
    1940             : {
    1941             :     struct colordesc *cd;
    1942          32 :     struct colordesc *end = CDEND(v->cm);
    1943             :     struct arc *a;
    1944             :     bool        israinbow;
    1945             : 
    1946             :     /*
    1947             :      * Scan lp's out-arcs and transiently mark the mentioned colors.  We
    1948             :      * expect that all of lp's out-arcs are plain, non-RAINBOW arcs to rp.
    1949             :      * (Note: there shouldn't be any pseudocolors yet, but check anyway.)
    1950             :      */
    1951          82 :     for (a = lp->outs; a != NULL; a = a->outchain)
    1952             :     {
    1953             :         assert(a->type == PLAIN);
    1954             :         assert(a->co >= 0);       /* i.e. not RAINBOW */
    1955             :         assert(a->to == rp);
    1956          50 :         cd = &v->cm->cd[a->co];
    1957             :         assert(!UNUSEDCOLOR(cd) && !(cd->flags & PSEUDO));
    1958          50 :         cd->flags |= COLMARK;
    1959             :     }
    1960             : 
    1961             :     /* Scan colors, clear transient marks, check for unmarked live colors */
    1962          32 :     israinbow = true;
    1963         124 :     for (cd = v->cm->cd; cd < end; cd++)
    1964             :     {
    1965          92 :         if (cd->flags & COLMARK)
    1966          50 :             cd->flags &= ~COLMARK;
    1967          42 :         else if (!UNUSEDCOLOR(cd) && !(cd->flags & PSEUDO))
    1968          28 :             israinbow = false;
    1969             :     }
    1970             : 
    1971             :     /* Can't do anything if not all colors have arcs */
    1972          32 :     if (!israinbow)
    1973          26 :         return;
    1974             : 
    1975             :     /* OK, drop existing arcs and replace with a rainbow */
    1976          18 :     while ((a = lp->outs) != NULL)
    1977          12 :         freearc(v->nfa, a);
    1978           6 :     newarc(v->nfa, PLAIN, RAINBOW, lp, rp);
    1979             : }
    1980             : 
    1981             : /*
    1982             :  * wordchrs - set up word-chr list for word-boundary stuff, if needed
    1983             :  *
    1984             :  * The list is kept as a bunch of circular arcs on an otherwise-unused state.
    1985             :  *
    1986             :  * Note that this must not be called while we have any open subcolors,
    1987             :  * else construction of the list would confuse color bookkeeping.
    1988             :  * Hence, we can't currently apply a similar optimization in
    1989             :  * charclass[complement](), as those need to be usable within bracket
    1990             :  * expressions.
    1991             :  */
    1992             : static void
    1993         166 : wordchrs(struct vars *v)
    1994             : {
    1995             :     struct state *cstate;
    1996             :     struct cvec *cv;
    1997             : 
    1998         166 :     if (v->wordchrs != NULL)
    1999          26 :         return;                 /* done already */
    2000             : 
    2001             :     /* make dummy state to hang the cache arcs on */
    2002         140 :     cstate = newstate(v->nfa);
    2003         140 :     NOERR();
    2004             : 
    2005             :     /* obtain possibly-cached cvec for \w characters */
    2006         140 :     NOTE(REG_ULOCALE);
    2007         140 :     cv = cclasscvec(v, CC_WORD, (v->cflags & REG_ICASE));
    2008         140 :     NOERR();
    2009             : 
    2010             :     /* build the arcs; this may cause color splitting */
    2011         140 :     subcolorcvec(v, cv, cstate, cstate);
    2012         140 :     NOERR();
    2013             : 
    2014             :     /* close new open subcolors to ensure the cache entry is self-contained */
    2015         140 :     okcolors(v->nfa, v->cm);
    2016         140 :     NOERR();
    2017             : 
    2018             :     /* success! save the cache pointer */
    2019         140 :     v->wordchrs = cstate;
    2020             : }
    2021             : 
    2022             : /*
    2023             :  * processlacon - generate the NFA representation of a LACON
    2024             :  *
    2025             :  * In the general case this is just newlacon() + newarc(), but some cases
    2026             :  * can be optimized.
    2027             :  */
    2028             : static void
    2029         254 : processlacon(struct vars *v,
    2030             :              struct state *begin,   /* start of parsed LACON sub-re */
    2031             :              struct state *end, /* end of parsed LACON sub-re */
    2032             :              int latype,
    2033             :              struct state *lp,  /* left state to hang it on */
    2034             :              struct state *rp)  /* right state to hang it on */
    2035             : {
    2036             :     struct state *s1;
    2037             :     int         n;
    2038             : 
    2039             :     /*
    2040             :      * Check for lookaround RE consisting of a single plain color arc (or set
    2041             :      * of arcs); this would typically be a simple chr or a bracket expression.
    2042             :      */
    2043         254 :     s1 = single_color_transition(begin, end);
    2044         254 :     switch (latype)
    2045             :     {
    2046          70 :         case LATYPE_AHEAD_POS:
    2047             :             /* If lookahead RE is just colorset C, convert to AHEAD(C) */
    2048          70 :             if (s1 != NULL)
    2049             :             {
    2050          60 :                 cloneouts(v->nfa, s1, lp, rp, AHEAD);
    2051          60 :                 return;
    2052             :             }
    2053          10 :             break;
    2054          78 :         case LATYPE_AHEAD_NEG:
    2055             :             /* If lookahead RE is just colorset C, convert to AHEAD(^C)|$ */
    2056          78 :             if (s1 != NULL)
    2057             :             {
    2058          20 :                 colorcomplement(v->nfa, v->cm, AHEAD, s1, lp, rp);
    2059          20 :                 newarc(v->nfa, '$', 1, lp, rp);
    2060          20 :                 newarc(v->nfa, '$', 0, lp, rp);
    2061          20 :                 return;
    2062             :             }
    2063          58 :             break;
    2064          78 :         case LATYPE_BEHIND_POS:
    2065             :             /* If lookbehind RE is just colorset C, convert to BEHIND(C) */
    2066          78 :             if (s1 != NULL)
    2067             :             {
    2068          60 :                 cloneouts(v->nfa, s1, lp, rp, BEHIND);
    2069          60 :                 return;
    2070             :             }
    2071          18 :             break;
    2072          28 :         case LATYPE_BEHIND_NEG:
    2073             :             /* If lookbehind RE is just colorset C, convert to BEHIND(^C)|^ */
    2074          28 :             if (s1 != NULL)
    2075             :             {
    2076          28 :                 colorcomplement(v->nfa, v->cm, BEHIND, s1, lp, rp);
    2077          28 :                 newarc(v->nfa, '^', 1, lp, rp);
    2078          28 :                 newarc(v->nfa, '^', 0, lp, rp);
    2079          28 :                 return;
    2080             :             }
    2081           0 :             break;
    2082          86 :         default:
    2083             :             assert(NOTREACHED);
    2084             :     }
    2085             : 
    2086             :     /* General case: we need a LACON subre and arc */
    2087          86 :     n = newlacon(v, begin, end, latype);
    2088          86 :     newarc(v->nfa, LACON, n, lp, rp);
    2089             : }
    2090             : 
    2091             : /*
    2092             :  * subre - allocate a subre
    2093             :  */
    2094             : static struct subre *
    2095       40888 : subre(struct vars *v,
    2096             :       int op,
    2097             :       int flags,
    2098             :       struct state *begin,
    2099             :       struct state *end)
    2100             : {
    2101       40888 :     struct subre *ret = v->treefree;
    2102             : 
    2103             :     /*
    2104             :      * Checking for stack overflow here is sufficient to protect parse() and
    2105             :      * its recursive subroutines.
    2106             :      */
    2107       40888 :     if (STACK_TOO_DEEP(v->re))
    2108             :     {
    2109           0 :         ERR(REG_ETOOBIG);
    2110           0 :         return NULL;
    2111             :     }
    2112             : 
    2113       40888 :     if (ret != NULL)
    2114        5836 :         v->treefree = ret->child;
    2115             :     else
    2116             :     {
    2117       35052 :         ret = (struct subre *) MALLOC(sizeof(struct subre));
    2118       35052 :         if (ret == NULL)
    2119             :         {
    2120           0 :             ERR(REG_ESPACE);
    2121           0 :             return NULL;
    2122             :         }
    2123       35052 :         ret->chain = v->treechain;
    2124       35052 :         v->treechain = ret;
    2125             :     }
    2126             : 
    2127             :     assert(strchr("=b|.*(", op) != NULL);
    2128             : 
    2129       40888 :     ret->op = op;
    2130       40888 :     ret->flags = flags;
    2131       40888 :     ret->latype = (char) -1;
    2132       40888 :     ret->id = 0;             /* will be assigned later */
    2133       40888 :     ret->capno = 0;
    2134       40888 :     ret->backno = 0;
    2135       40888 :     ret->min = ret->max = 1;
    2136       40888 :     ret->child = NULL;
    2137       40888 :     ret->sibling = NULL;
    2138       40888 :     ret->begin = begin;
    2139       40888 :     ret->end = end;
    2140       40888 :     ZAPCNFA(ret->cnfa);
    2141             : 
    2142       40888 :     return ret;
    2143             : }
    2144             : 
    2145             : /*
    2146             :  * freesubre - free a subRE subtree
    2147             :  *
    2148             :  * This frees child node(s) of the given subRE too,
    2149             :  * but not its siblings.
    2150             :  */
    2151             : static void
    2152       18924 : freesubre(struct vars *v,       /* might be NULL */
    2153             :           struct subre *sr)
    2154             : {
    2155       18924 :     if (sr == NULL)
    2156          14 :         return;
    2157             : 
    2158       18910 :     if (sr->child != NULL)
    2159        1394 :         freesubreandsiblings(v, sr->child);
    2160             : 
    2161       18910 :     freesrnode(v, sr);
    2162             : }
    2163             : 
    2164             : /*
    2165             :  * freesubreandsiblings - free a subRE subtree
    2166             :  *
    2167             :  * This frees child node(s) of the given subRE too,
    2168             :  * as well as any following siblings.
    2169             :  */
    2170             : static void
    2171        8194 : freesubreandsiblings(struct vars *v,    /* might be NULL */
    2172             :                      struct subre *sr)
    2173             : {
    2174       24160 :     while (sr != NULL)
    2175             :     {
    2176       15966 :         struct subre *next = sr->sibling;
    2177             : 
    2178       15966 :         freesubre(v, sr);
    2179       15966 :         sr = next;
    2180             :     }
    2181        8194 : }
    2182             : 
    2183             : /*
    2184             :  * freesrnode - free one node in a subRE subtree
    2185             :  */
    2186             : static void
    2187       32288 : freesrnode(struct vars *v,      /* might be NULL */
    2188             :            struct subre *sr)
    2189             : {
    2190       32288 :     if (sr == NULL)
    2191           0 :         return;
    2192             : 
    2193       32288 :     if (!NULLCNFA(sr->cnfa))
    2194        2960 :         freecnfa(&sr->cnfa);
    2195       32288 :     sr->flags = 0;               /* in particular, not INUSE */
    2196       32288 :     sr->child = sr->sibling = NULL;
    2197       32288 :     sr->begin = sr->end = NULL;
    2198             : 
    2199       32288 :     if (v != NULL && v->treechain != NULL)
    2200             :     {
    2201             :         /* we're still parsing, maybe we can reuse the subre */
    2202       29322 :         sr->child = v->treefree;
    2203       29322 :         v->treefree = sr;
    2204             :     }
    2205             :     else
    2206        2966 :         FREE(sr);
    2207             : }
    2208             : 
    2209             : /*
    2210             :  * removecaptures - remove unnecessary capture subREs
    2211             :  *
    2212             :  * If the caller said that it doesn't care about subexpression match data,
    2213             :  * we may delete the "capture" markers on subREs that are not referenced
    2214             :  * by any backrefs, and then simplify anything that's become non-messy.
    2215             :  * Call this only if REG_NOSUB flag is set.
    2216             :  */
    2217             : static void
    2218       18794 : removecaptures(struct vars *v,
    2219             :                struct subre *t)
    2220             : {
    2221             :     struct subre *t2;
    2222             : 
    2223             :     assert(t != NULL);
    2224             : 
    2225             :     /*
    2226             :      * If this isn't itself a backref target, clear capno and tentatively
    2227             :      * clear CAP flag.
    2228             :      */
    2229       18794 :     if (!(t->flags & BRUSE))
    2230             :     {
    2231       18720 :         t->capno = 0;
    2232       18720 :         t->flags &= ~CAP;
    2233             :     }
    2234             : 
    2235             :     /* Now recurse to children */
    2236       32350 :     for (t2 = t->child; t2 != NULL; t2 = t2->sibling)
    2237             :     {
    2238       13556 :         removecaptures(v, t2);
    2239             :         /* Propagate child CAP flag back up, if it's still set */
    2240       13556 :         if (t2->flags & CAP)
    2241         148 :             t->flags |= CAP;
    2242             :     }
    2243             : 
    2244             :     /*
    2245             :      * If t now contains neither captures nor backrefs, there's no longer any
    2246             :      * need to care where its sub-match boundaries are, so we can reduce it to
    2247             :      * a simple DFA node.  (Note in particular that MIXED child greediness is
    2248             :      * not a hindrance here, so we don't use the MESSY() macro.)
    2249             :      */
    2250       18794 :     if ((t->flags & (CAP | BACKR)) == 0)
    2251             :     {
    2252       18400 :         if (t->child)
    2253        6596 :             freesubreandsiblings(v, t->child);
    2254       18400 :         t->child = NULL;
    2255       18400 :         t->op = '=';
    2256       18400 :         t->flags &= ~MIXED;
    2257             :     }
    2258       18794 : }
    2259             : 
    2260             : /*
    2261             :  * numst - number tree nodes (assigning "id" indexes)
    2262             :  */
    2263             : static int                      /* next number */
    2264       10844 : numst(struct subre *t,
    2265             :       int start)                /* starting point for subtree numbers */
    2266             : {
    2267             :     int         i;
    2268             :     struct subre *t2;
    2269             : 
    2270             :     assert(t != NULL);
    2271             : 
    2272       10844 :     i = start;
    2273       10844 :     t->id = i++;
    2274       14540 :     for (t2 = t->child; t2 != NULL; t2 = t2->sibling)
    2275        3696 :         i = numst(t2, i);
    2276       10844 :     return i;
    2277             : }
    2278             : 
    2279             : /*
    2280             :  * markst - mark tree nodes as INUSE
    2281             :  *
    2282             :  * Note: this is a great deal more subtle than it looks.  During initial
    2283             :  * parsing of a regex, all subres are linked into the treechain list;
    2284             :  * discarded ones are also linked into the treefree list for possible reuse.
    2285             :  * After we are done creating all subres required for a regex, we run markst()
    2286             :  * then cleanst(), which results in discarding all subres not reachable from
    2287             :  * v->tree.  We then clear v->treechain, indicating that subres must be found
    2288             :  * by descending from v->tree.  This changes the behavior of freesubre(): it
    2289             :  * will henceforth FREE() unwanted subres rather than sticking them into the
    2290             :  * treefree list.  (Doing that any earlier would result in dangling links in
    2291             :  * the treechain list.)  This all means that freev() will clean up correctly
    2292             :  * if invoked before or after markst()+cleanst(); but it would not work if
    2293             :  * called partway through this state conversion, so we mustn't error out
    2294             :  * in or between these two functions.
    2295             :  */
    2296             : static void
    2297       10844 : markst(struct subre *t)
    2298             : {
    2299             :     struct subre *t2;
    2300             : 
    2301             :     assert(t != NULL);
    2302             : 
    2303       10844 :     t->flags |= INUSE;
    2304       14540 :     for (t2 = t->child; t2 != NULL; t2 = t2->sibling)
    2305        3696 :         markst(t2);
    2306       10844 : }
    2307             : 
    2308             : /*
    2309             :  * cleanst - free any tree nodes not marked INUSE
    2310             :  */
    2311             : static void
    2312        7372 : cleanst(struct vars *v)
    2313             : {
    2314             :     struct subre *t;
    2315             :     struct subre *next;
    2316             : 
    2317       42424 :     for (t = v->treechain; t != NULL; t = next)
    2318             :     {
    2319       35052 :         next = t->chain;
    2320       35052 :         if (!(t->flags & INUSE))
    2321       24208 :             FREE(t);
    2322             :     }
    2323        7372 :     v->treechain = NULL;
    2324        7372 :     v->treefree = NULL;          /* just on general principles */
    2325        7372 : }
    2326             : 
    2327             : /*
    2328             :  * nfatree - turn a subRE subtree into a tree of compacted NFAs
    2329             :  */
    2330             : static long                     /* optimize results from top node */
    2331       10844 : nfatree(struct vars *v,
    2332             :         struct subre *t,
    2333             :         FILE *f)                /* for debug output */
    2334             : {
    2335             :     struct subre *t2;
    2336             : 
    2337             :     assert(t != NULL && t->begin != NULL);
    2338             : 
    2339       14540 :     for (t2 = t->child; t2 != NULL; t2 = t2->sibling)
    2340        3696 :         (DISCARD) nfatree(v, t2, f);
    2341             : 
    2342       10844 :     return nfanode(v, t, 0, f);
    2343             : }
    2344             : 
    2345             : /*
    2346             :  * nfanode - do one NFA for nfatree or lacons
    2347             :  *
    2348             :  * If converttosearch is true, apply makesearch() to the NFA.
    2349             :  */
    2350             : static long                     /* optimize results */
    2351       10930 : nfanode(struct vars *v,
    2352             :         struct subre *t,
    2353             :         int converttosearch,
    2354             :         FILE *f)                /* for debug output */
    2355             : {
    2356             :     struct nfa *nfa;
    2357       10930 :     long        ret = 0;
    2358             : 
    2359             :     assert(t->begin != NULL);
    2360             : 
    2361             : #ifdef REG_DEBUG
    2362             :     if (f != NULL)
    2363             :     {
    2364             :         char        idbuf[50];
    2365             : 
    2366             :         fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
    2367             :                 stid(t, idbuf, sizeof(idbuf)));
    2368             :     }
    2369             : #endif
    2370       10930 :     nfa = newnfa(v, v->cm, v->nfa);
    2371       10930 :     NOERRZ();
    2372       10930 :     dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
    2373       10930 :     nfa->flags = v->nfa->flags;
    2374       10930 :     if (!ISERR())
    2375       10930 :         specialcolors(nfa);
    2376       10930 :     if (!ISERR())
    2377       10930 :         ret = optimize(nfa, f);
    2378       10930 :     if (converttosearch && !ISERR())
    2379          18 :         makesearch(v, nfa);
    2380       10930 :     if (!ISERR())
    2381       10924 :         compact(nfa, &t->cnfa);
    2382             : 
    2383       10930 :     freenfa(nfa);
    2384       10930 :     return ret;
    2385             : }
    2386             : 
    2387             : /*
    2388             :  * newlacon - allocate a lookaround-constraint subRE
    2389             :  */
    2390             : static int                      /* lacon number */
    2391          86 : newlacon(struct vars *v,
    2392             :          struct state *begin,
    2393             :          struct state *end,
    2394             :          int latype)
    2395             : {
    2396             :     int         n;
    2397             :     struct subre *newlacons;
    2398             :     struct subre *sub;
    2399             : 
    2400          86 :     if (v->nlacons == 0)
    2401             :     {
    2402          58 :         n = 1;                  /* skip 0th */
    2403          58 :         newlacons = (struct subre *) MALLOC(2 * sizeof(struct subre));
    2404             :     }
    2405             :     else
    2406             :     {
    2407          28 :         n = v->nlacons;
    2408          28 :         newlacons = (struct subre *) REALLOC(v->lacons,
    2409             :                                              (n + 1) * sizeof(struct subre));
    2410             :     }
    2411          86 :     if (newlacons == NULL)
    2412             :     {
    2413           0 :         ERR(REG_ESPACE);
    2414           0 :         return 0;
    2415             :     }
    2416          86 :     v->lacons = newlacons;
    2417          86 :     v->nlacons = n + 1;
    2418          86 :     sub = &v->lacons[n];
    2419          86 :     sub->begin = begin;
    2420          86 :     sub->end = end;
    2421          86 :     sub->latype = latype;
    2422          86 :     ZAPCNFA(sub->cnfa);
    2423          86 :     return n;
    2424             : }
    2425             : 
    2426             : /*
    2427             :  * freelacons - free lookaround-constraint subRE vector
    2428             :  */
    2429             : static void
    2430          20 : freelacons(struct subre *subs,
    2431             :            int n)
    2432             : {
    2433             :     struct subre *sub;
    2434             :     int         i;
    2435             : 
    2436             :     assert(n > 0);
    2437          56 :     for (sub = subs + 1, i = n - 1; i > 0; sub++, i--)   /* no 0th */
    2438          36 :         if (!NULLCNFA(sub->cnfa))
    2439          36 :             freecnfa(&sub->cnfa);
    2440          20 :     FREE(subs);
    2441          20 : }
    2442             : 
    2443             : /*
    2444             :  * rfree - free a whole RE (insides of regfree)
    2445             :  */
    2446             : static void
    2447        1544 : rfree(regex_t *re)
    2448             : {
    2449             :     struct guts *g;
    2450             : 
    2451        1544 :     if (re == NULL || re->re_magic != REMAGIC)
    2452           0 :         return;
    2453             : 
    2454        1544 :     re->re_magic = 0;            /* invalidate RE */
    2455        1544 :     g = (struct guts *) re->re_guts;
    2456        1544 :     re->re_guts = NULL;
    2457        1544 :     re->re_fns = NULL;
    2458        1544 :     if (g != NULL)
    2459             :     {
    2460        1544 :         g->magic = 0;
    2461        1544 :         freecm(&g->cmap);
    2462        1544 :         if (g->tree != NULL)
    2463        1300 :             freesubre((struct vars *) NULL, g->tree);
    2464        1544 :         if (g->lacons != NULL)
    2465          20 :             freelacons(g->lacons, g->nlacons);
    2466        1544 :         if (!NULLCNFA(g->search))
    2467        1300 :             freecnfa(&g->search);
    2468        1544 :         FREE(g);
    2469             :     }
    2470             : }
    2471             : 
    2472             : /*
    2473             :  * rstacktoodeep - check for stack getting dangerously deep
    2474             :  *
    2475             :  * Return nonzero to fail the operation with error code REG_ETOOBIG,
    2476             :  * zero to keep going
    2477             :  *
    2478             :  * The current implementation is Postgres-specific.  If we ever get around
    2479             :  * to splitting the regex code out as a standalone library, there will need
    2480             :  * to be some API to let applications define a callback function for this.
    2481             :  */
    2482             : static int
    2483    21722472 : rstacktoodeep(void)
    2484             : {
    2485    21722472 :     return stack_is_too_deep();
    2486             : }
    2487             : 
    2488             : #ifdef REG_DEBUG
    2489             : 
    2490             : /*
    2491             :  * dump - dump an RE in human-readable form
    2492             :  */
    2493             : static void
    2494             : dump(regex_t *re,
    2495             :      FILE *f)
    2496             : {
    2497             :     struct guts *g;
    2498             :     int         i;
    2499             : 
    2500             :     if (re->re_magic != REMAGIC)
    2501             :         fprintf(f, "bad magic number (0x%x not 0x%x)\n", re->re_magic,
    2502             :                 REMAGIC);
    2503             :     if (re->re_guts == NULL)
    2504             :     {
    2505             :         fprintf(f, "NULL guts!!!\n");
    2506             :         return;
    2507             :     }
    2508             :     g = (struct guts *) re->re_guts;
    2509             :     if (g->magic != GUTSMAGIC)
    2510             :         fprintf(f, "bad guts magic number (0x%x not 0x%x)\n", g->magic,
    2511             :                 GUTSMAGIC);
    2512             : 
    2513             :     fprintf(f, "\n\n\n========= DUMP ==========\n");
    2514             :     fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n",
    2515             :             (int) re->re_nsub, re->re_info, re->re_csize, g->ntree);
    2516             : 
    2517             :     dumpcolors(&g->cmap, f);
    2518             :     if (!NULLCNFA(g->search))
    2519             :     {
    2520             :         fprintf(f, "\nsearch:\n");
    2521             :         dumpcnfa(&g->search, f);
    2522             :     }
    2523             :     for (i = 1; i < g->nlacons; i++)
    2524             :     {
    2525             :         struct subre *lasub = &g->lacons[i];
    2526             :         const char *latype;
    2527             : 
    2528             :         switch (lasub->latype)
    2529             :         {
    2530             :             case LATYPE_AHEAD_POS:
    2531             :                 latype = "positive lookahead";
    2532             :                 break;
    2533             :             case LATYPE_AHEAD_NEG:
    2534             :                 latype = "negative lookahead";
    2535             :                 break;
    2536             :             case LATYPE_BEHIND_POS:
    2537             :                 latype = "positive lookbehind";
    2538             :                 break;
    2539             :             case LATYPE_BEHIND_NEG:
    2540             :                 latype = "negative lookbehind";
    2541             :                 break;
    2542             :             default:
    2543             :                 latype = "???";
    2544             :                 break;
    2545             :         }
    2546             :         fprintf(f, "\nla%d (%s):\n", i, latype);
    2547             :         dumpcnfa(&lasub->cnfa, f);
    2548             :     }
    2549             :     fprintf(f, "\n");
    2550             :     dumpst(g->tree, f, 0);
    2551             : }
    2552             : 
    2553             : /*
    2554             :  * dumpst - dump a subRE tree
    2555             :  */
    2556             : static void
    2557             : dumpst(struct subre *t,
    2558             :        FILE *f,
    2559             :        int nfapresent)          /* is the original NFA still around? */
    2560             : {
    2561             :     if (t == NULL)
    2562             :         fprintf(f, "null tree\n");
    2563             :     else
    2564             :         stdump(t, f, nfapresent);
    2565             :     fflush(f);
    2566             : }
    2567             : 
    2568             : /*
    2569             :  * stdump - recursive guts of dumpst
    2570             :  */
    2571             : static void
    2572             : stdump(struct subre *t,
    2573             :        FILE *f,
    2574             :        int nfapresent)          /* is the original NFA still around? */
    2575             : {
    2576             :     char        idbuf[50];
    2577             :     struct subre *t2;
    2578             : 
    2579             :     fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op);
    2580             :     if (t->flags & LONGER)
    2581             :         fprintf(f, " longest");
    2582             :     if (t->flags & SHORTER)
    2583             :         fprintf(f, " shortest");
    2584             :     if (t->flags & MIXED)
    2585             :         fprintf(f, " hasmixed");
    2586             :     if (t->flags & CAP)
    2587             :         fprintf(f, " hascapture");
    2588             :     if (t->flags & BACKR)
    2589             :         fprintf(f, " hasbackref");
    2590             :     if (t->flags & BRUSE)
    2591             :         fprintf(f, " isreferenced");
    2592             :     if (!(t->flags & INUSE))
    2593             :         fprintf(f, " UNUSED");
    2594             :     if (t->latype != (char) -1)
    2595             :         fprintf(f, " latype(%d)", t->latype);
    2596             :     if (t->capno != 0)
    2597             :         fprintf(f, " capture(%d)", t->capno);
    2598             :     if (t->backno != 0)
    2599             :         fprintf(f, " backref(%d)", t->backno);
    2600             :     if (t->min != 1 || t->max != 1)
    2601             :     {
    2602             :         fprintf(f, " {%d,", t->min);
    2603             :         if (t->max != DUPINF)
    2604             :             fprintf(f, "%d", t->max);
    2605             :         fprintf(f, "}");
    2606             :     }
    2607             :     if (nfapresent)
    2608             :         fprintf(f, " %ld-%ld", (long) t->begin->no, (long) t->end->no);
    2609             :     if (t->child != NULL)
    2610             :         fprintf(f, " C:%s", stid(t->child, idbuf, sizeof(idbuf)));
    2611             :     /* printing second child isn't necessary, but it is often helpful */
    2612             :     if (t->child != NULL && t->child->sibling != NULL)
    2613             :         fprintf(f, " C2:%s", stid(t->child->sibling, idbuf, sizeof(idbuf)));
    2614             :     if (t->sibling != NULL)
    2615             :         fprintf(f, " S:%s", stid(t->sibling, idbuf, sizeof(idbuf)));
    2616             :     if (!NULLCNFA(t->cnfa))
    2617             :     {
    2618             :         fprintf(f, "\n");
    2619             :         dumpcnfa(&t->cnfa, f);
    2620             :     }
    2621             :     fprintf(f, "\n");
    2622             :     for (t2 = t->child; t2 != NULL; t2 = t2->sibling)
    2623             :         stdump(t2, f, nfapresent);
    2624             : }
    2625             : 
    2626             : /*
    2627             :  * stid - identify a subtree node for dumping
    2628             :  */
    2629             : static const char *             /* points to buf or constant string */
    2630             : stid(struct subre *t,
    2631             :      char *buf,
    2632             :      size_t bufsize)
    2633             : {
    2634             :     /* big enough for hex int or decimal t->id? */
    2635             :     if (bufsize < sizeof(void *) * 2 + 3 || bufsize < sizeof(t->id) * 3 + 1)
    2636             :         return "unable";
    2637             :     if (t->id != 0)
    2638             :         sprintf(buf, "%d", t->id);
    2639             :     else
    2640             :         sprintf(buf, "%p", t);
    2641             :     return buf;
    2642             : }
    2643             : #endif                          /* REG_DEBUG */
    2644             : 
    2645             : 
    2646             : #include "regc_lex.c"
    2647             : #include "regc_color.c"
    2648             : #include "regc_nfa.c"
    2649             : #include "regc_cvec.c"
    2650             : #include "regc_pg_locale.c"
    2651             : #include "regc_locale.c"

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