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regcomp.c

/*
 * re_*comp and friends - compile REs
 * This file #includes several others (see the bottom).
 *
 * Copyright (c) 1998, 1999 Henry Spencer.  All rights reserved.
 * 
 * Development of this software was funded, in part, by Cray Research Inc.,
 * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
 * Corporation, none of whom are responsible for the results.  The author
 * thanks all of them. 
 * 
 * Redistribution and use in source and binary forms -- with or without
 * modification -- are permitted for any purpose, provided that
 * redistributions in source form retain this entire copyright notice and
 * indicate the origin and nature of any modifications.
 * 
 * I'd appreciate being given credit for this package in the documentation
 * of software which uses it, but that is not a requirement.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "regguts.h"

/*
 * forward declarations, up here so forward datatypes etc. are defined early
 */
/* =====^!^===== begin forwards =====^!^===== */
/* automatically gathered by fwd; do not hand-edit */
/* === regcomp.c === */
int compile _ANSI_ARGS_((regex_t *, CONST chr *, size_t, int));
static VOID moresubs _ANSI_ARGS_((struct vars *, int));
static int freev _ANSI_ARGS_((struct vars *, int));
static VOID makesearch _ANSI_ARGS_((struct vars *, struct nfa *));
static struct subre *parse _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *));
static struct subre *parsebranch _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *, int));
static VOID parseqatom _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *, struct subre *));
static VOID nonword _ANSI_ARGS_((struct vars *, int, struct state *, struct state *));
static VOID word _ANSI_ARGS_((struct vars *, int, struct state *, struct state *));
static int scannum _ANSI_ARGS_((struct vars *));
static VOID repeat _ANSI_ARGS_((struct vars *, struct state *, struct state *, int, int));
static VOID bracket _ANSI_ARGS_((struct vars *, struct state *, struct state *));
static VOID cbracket _ANSI_ARGS_((struct vars *, struct state *, struct state *));
static VOID brackpart _ANSI_ARGS_((struct vars *, struct state *, struct state *));
static chr *scanplain _ANSI_ARGS_((struct vars *));
static VOID leaders _ANSI_ARGS_((struct vars *, struct cvec *));
static VOID onechr _ANSI_ARGS_((struct vars *, pchr, struct state *, struct state *));
static VOID dovec _ANSI_ARGS_((struct vars *, struct cvec *, struct state *, struct state *));
static celt nextleader _ANSI_ARGS_((struct vars *, pchr, pchr));
static VOID wordchrs _ANSI_ARGS_((struct vars *));
static struct subre *subre _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *));
static VOID freesubre _ANSI_ARGS_((struct vars *, struct subre *));
static VOID freesrnode _ANSI_ARGS_((struct vars *, struct subre *));
static VOID optst _ANSI_ARGS_((struct vars *, struct subre *));
static int numst _ANSI_ARGS_((struct subre *, int));
static VOID markst _ANSI_ARGS_((struct subre *));
static VOID cleanst _ANSI_ARGS_((struct vars *));
static long nfatree _ANSI_ARGS_((struct vars *, struct subre *, FILE *));
static long nfanode _ANSI_ARGS_((struct vars *, struct subre *, FILE *));
static int newlacon _ANSI_ARGS_((struct vars *, struct state *, struct state *, int));
static VOID freelacons _ANSI_ARGS_((struct subre *, int));
static VOID rfree _ANSI_ARGS_((regex_t *));
static VOID dump _ANSI_ARGS_((regex_t *, FILE *));
static VOID dumpst _ANSI_ARGS_((struct subre *, FILE *, int));
static VOID stdump _ANSI_ARGS_((struct subre *, FILE *, int));
static char *stid _ANSI_ARGS_((struct subre *, char *, size_t));
/* === regc_lex.c === */
static VOID lexstart _ANSI_ARGS_((struct vars *));
static VOID prefixes _ANSI_ARGS_((struct vars *));
static VOID lexnest _ANSI_ARGS_((struct vars *, chr *, chr *));
static VOID lexword _ANSI_ARGS_((struct vars *));
static int next _ANSI_ARGS_((struct vars *));
static int lexescape _ANSI_ARGS_((struct vars *));
static chr lexdigits _ANSI_ARGS_((struct vars *, int, int, int));
static int brenext _ANSI_ARGS_((struct vars *, pchr));
static VOID skip _ANSI_ARGS_((struct vars *));
static chr newline _ANSI_ARGS_((NOPARMS));
#ifdef REG_DEBUG
static chr *ch _ANSI_ARGS_((NOPARMS));
#endif
static chr chrnamed _ANSI_ARGS_((struct vars *, chr *, chr *, pchr));
/* === regc_color.c === */
static VOID initcm _ANSI_ARGS_((struct vars *, struct colormap *));
static VOID freecm _ANSI_ARGS_((struct colormap *));
static VOID cmtreefree _ANSI_ARGS_((struct colormap *, union tree *, int));
static color setcolor _ANSI_ARGS_((struct colormap *, pchr, pcolor));
static color maxcolor _ANSI_ARGS_((struct colormap *));
static color newcolor _ANSI_ARGS_((struct colormap *));
static VOID freecolor _ANSI_ARGS_((struct colormap *, pcolor));
static color pseudocolor _ANSI_ARGS_((struct colormap *));
static color subcolor _ANSI_ARGS_((struct colormap *, pchr c));
static color newsub _ANSI_ARGS_((struct colormap *, pcolor));
static VOID subrange _ANSI_ARGS_((struct vars *, pchr, pchr, struct state *, struct state *));
static VOID subblock _ANSI_ARGS_((struct vars *, pchr, struct state *, struct state *));
static VOID okcolors _ANSI_ARGS_((struct nfa *, struct colormap *));
static VOID colorchain _ANSI_ARGS_((struct colormap *, struct arc *));
static VOID uncolorchain _ANSI_ARGS_((struct colormap *, struct arc *));
static int singleton _ANSI_ARGS_((struct colormap *, pchr c));
static VOID rainbow _ANSI_ARGS_((struct nfa *, struct colormap *, int, pcolor, struct state *, struct state *));
static VOID colorcomplement _ANSI_ARGS_((struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *));
#ifdef REG_DEBUG
static VOID dumpcolors _ANSI_ARGS_((struct colormap *, FILE *));
static VOID fillcheck _ANSI_ARGS_((struct colormap *, union tree *, int, FILE *));
static VOID dumpchr _ANSI_ARGS_((pchr, FILE *));
#endif
/* === regc_nfa.c === */
static struct nfa *newnfa _ANSI_ARGS_((struct vars *, struct colormap *, struct nfa *));
static VOID freenfa _ANSI_ARGS_((struct nfa *));
static struct state *newstate _ANSI_ARGS_((struct nfa *));
static struct state *newfstate _ANSI_ARGS_((struct nfa *, int flag));
static VOID dropstate _ANSI_ARGS_((struct nfa *, struct state *));
static VOID freestate _ANSI_ARGS_((struct nfa *, struct state *));
static VOID destroystate _ANSI_ARGS_((struct nfa *, struct state *));
static VOID newarc _ANSI_ARGS_((struct nfa *, int, pcolor, struct state *, struct state *));
static struct arc *allocarc _ANSI_ARGS_((struct nfa *, struct state *));
static VOID freearc _ANSI_ARGS_((struct nfa *, struct arc *));
static struct arc *findarc _ANSI_ARGS_((struct state *, int, pcolor));
static VOID cparc _ANSI_ARGS_((struct nfa *, struct arc *, struct state *, struct state *));
static VOID moveins _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
static VOID copyins _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
static VOID moveouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
static VOID copyouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
static VOID cloneouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *, int));
static VOID delsub _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
static VOID deltraverse _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
static VOID dupnfa _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *, struct state *));
static VOID duptraverse _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
static VOID cleartraverse _ANSI_ARGS_((struct nfa *, struct state *));
static VOID specialcolors _ANSI_ARGS_((struct nfa *));
static long optimize _ANSI_ARGS_((struct nfa *, FILE *));
static VOID pullback _ANSI_ARGS_((struct nfa *, FILE *));
static int pull _ANSI_ARGS_((struct nfa *, struct arc *));
static VOID pushfwd _ANSI_ARGS_((struct nfa *, FILE *));
static int push _ANSI_ARGS_((struct nfa *, struct arc *));
#define     INCOMPATIBLE      1     /* destroys arc */
#define     SATISFIED   2     /* constraint satisfied */
#define     COMPATIBLE  3     /* compatible but not satisfied yet */
static int combine _ANSI_ARGS_((struct arc *, struct arc *));
static VOID fixempties _ANSI_ARGS_((struct nfa *, FILE *));
static int unempty _ANSI_ARGS_((struct nfa *, struct arc *));
static VOID cleanup _ANSI_ARGS_((struct nfa *));
static VOID markreachable _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *));
static VOID markcanreach _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *));
static long analyze _ANSI_ARGS_((struct nfa *));
static VOID compact _ANSI_ARGS_((struct nfa *, struct cnfa *));
static VOID carcsort _ANSI_ARGS_((struct carc *, struct carc *));
static VOID freecnfa _ANSI_ARGS_((struct cnfa *));
static VOID dumpnfa _ANSI_ARGS_((struct nfa *, FILE *));
#ifdef REG_DEBUG
static VOID dumpstate _ANSI_ARGS_((struct state *, FILE *));
static VOID dumparcs _ANSI_ARGS_((struct state *, FILE *));
static int dumprarcs _ANSI_ARGS_((struct arc *, struct state *, FILE *, int));
static VOID dumparc _ANSI_ARGS_((struct arc *, struct state *, FILE *));
#endif
static VOID dumpcnfa _ANSI_ARGS_((struct cnfa *, FILE *));
#ifdef REG_DEBUG
static VOID dumpcstate _ANSI_ARGS_((int, struct carc *, struct cnfa *, FILE *));
#endif
/* === regc_cvec.c === */
static struct cvec *newcvec _ANSI_ARGS_((int, int, int));
static struct cvec *clearcvec _ANSI_ARGS_((struct cvec *));
static VOID addchr _ANSI_ARGS_((struct cvec *, pchr));
static VOID addrange _ANSI_ARGS_((struct cvec *, pchr, pchr));
static VOID addmcce _ANSI_ARGS_((struct cvec *, chr *, chr *));
static int haschr _ANSI_ARGS_((struct cvec *, pchr));
static struct cvec *getcvec _ANSI_ARGS_((struct vars *, int, int, int));
static VOID freecvec _ANSI_ARGS_((struct cvec *));
/* === regc_locale.c === */
static int nmcces _ANSI_ARGS_((struct vars *));
static int nleaders _ANSI_ARGS_((struct vars *));
static struct cvec *allmcces _ANSI_ARGS_((struct vars *, struct cvec *));
static celt element _ANSI_ARGS_((struct vars *, chr *, chr *));
static struct cvec *range _ANSI_ARGS_((struct vars *, celt, celt, int));
static int before _ANSI_ARGS_((celt, celt));
static struct cvec *eclass _ANSI_ARGS_((struct vars *, celt, int));
static struct cvec *cclass _ANSI_ARGS_((struct vars *, chr *, chr *, int));
static struct cvec *allcases _ANSI_ARGS_((struct vars *, pchr));
static int cmp _ANSI_ARGS_((CONST chr *, CONST chr *, size_t));
static int casecmp _ANSI_ARGS_((CONST chr *, CONST chr *, size_t));
/* automatically gathered by fwd; do not hand-edit */
/* =====^!^===== end forwards =====^!^===== */



/* internal variables, bundled for easy passing around */
struct vars {
      regex_t *re;
      chr *now;         /* scan pointer into string */
      chr *stop;        /* end of string */
      chr *savenow;           /* saved now and stop for "subroutine call" */
      chr *savestop;
      int err;          /* error code (0 if none) */
      int cflags;       /* copy of compile flags */
      int lasttype;           /* type of previous token */
      int nexttype;           /* type of next token */
      chr nextvalue;          /* value (if any) of next token */
      int lexcon;       /* lexical context type (see lex.c) */
      int nsubexp;            /* subexpression count */
      struct subre **subs;    /* subRE pointer vector */
      size_t nsubs;           /* length of vector */
      struct subre *sub10[10];      /* initial vector, enough for most */
      struct nfa *nfa;  /* the NFA */
      struct colormap *cm;    /* character color map */
      color nlcolor;          /* color of newline */
      struct state *wordchrs; /* state in nfa holding word-char outarcs */
      struct subre *tree;     /* subexpression tree */
      struct subre *treechain;      /* all tree nodes allocated */
      struct subre *treefree;       /* any free tree nodes */
      int ntree;        /* number of tree nodes */
      struct cvec *cv;  /* interface cvec */
      struct cvec *cv2; /* utility cvec */
      struct cvec *mcces;     /* collating-element information */
#           define      ISCELEADER(v,c)   (v->mcces != NULL && haschr(v->mcces, (c)))
      struct state *mccepbegin;     /* in nfa, start of MCCE prototypes */
      struct state *mccepend; /* in nfa, end of MCCE prototypes */
      struct subre *lacons;   /* lookahead-constraint vector */
      int nlacons;            /* size of lacons */
};

/* parsing macros; most know that `v' is the struct vars pointer */
#define     NEXT()      (next(v))         /* advance by one token */
#define     SEE(t)      (v->nexttype == (t))    /* is next token this? */
#define     EAT(t)      (SEE(t) && next(v))     /* if next is this, swallow it */
#define     VISERR(vv)  ((vv)->err != 0)  /* have we seen an error yet? */
#define     ISERR()     VISERR(v)
#define     VERR(vv,e)  ((vv)->nexttype = EOS, ((vv)->err) ? (vv)->err :\
                                          ((vv)->err = (e)))
#define     ERR(e)      VERR(v, e)        /* record an error */
#define     NOERR()     {if (ISERR()) return;}  /* if error seen, return */
#define     NOERRN()    {if (ISERR()) return NULL;}   /* NOERR with retval */
#define     NOERRZ()    {if (ISERR()) return 0;}      /* NOERR with retval */
#define     INSIST(c, e)      ((c) ? 0 : ERR(e))      /* if condition false, error */
#define     NOTE(b)     (v->re->re_info |= (b))       /* note visible condition */
#define     EMPTYARC(x, y)    newarc(v->nfa, EMPTY, 0, x, y)

/* token type codes, some also used as NFA arc types */
#define     EMPTY 'n'         /* no token present */
#define     EOS   'e'         /* end of string */
#define     PLAIN 'p'         /* ordinary character */
#define     DIGIT 'd'         /* digit (in bound) */
#define     BACKREF     'b'         /* back reference */
#define     COLLEL      'I'         /* start of [. */
#define     ECLASS      'E'         /* start of [= */
#define     CCLASS      'C'         /* start of [: */
#define     END   'X'         /* end of [. [= [: */
#define     RANGE 'R'         /* - within [] which might be range delim. */
#define     LACON 'L'         /* lookahead constraint subRE */
#define     AHEAD 'a'         /* color-lookahead arc */
#define     BEHIND      'r'         /* color-lookbehind arc */
#define     WBDRY 'w'         /* word boundary constraint */
#define     NWBDRY      'W'         /* non-word-boundary constraint */
#define     SBEGIN      'A'         /* beginning of string (even if not BOL) */
#define     SEND  'Z'         /* end of string (even if not EOL) */
#define     PREFER      'P'         /* length preference */

/* is an arc colored, and hence on a color chain? */
#define     COLORED(a)  ((a)->type == PLAIN || (a)->type == AHEAD || \
                                          (a)->type == BEHIND)



/* static function list */
static struct fns functions = {
      rfree,                  /* regfree insides */
};



/*
 - compile - compile regular expression
 ^ int compile(regex_t *, CONST chr *, size_t, int);
 */
int
compile(re, string, len, flags)
regex_t *re;
CONST chr *string;
size_t len;
int flags;
{
      struct vars var;
      struct vars *v = &var;
      struct guts *g;
      int i;
      size_t j;
      FILE *debug = (flags&REG_PROGRESS) ? stdout : (FILE *)NULL;
#     define      CNOERR()    { if (ISERR()) return freev(v, v->err); }

      /* sanity checks */

      if (re == NULL || string == NULL)
            return REG_INVARG;
      if ((flags&REG_QUOTE) &&
                  (flags&(REG_ADVANCED|REG_EXPANDED|REG_NEWLINE)))
            return REG_INVARG;
      if (!(flags&REG_EXTENDED) && (flags&REG_ADVF))
            return REG_INVARG;

      /* initial setup (after which freev() is callable) */
      v->re = re;
      v->now = (chr *)string;
      v->stop = v->now + len;
      v->savenow = v->savestop = NULL;
      v->err = 0;
      v->cflags = flags;
      v->nsubexp = 0;
      v->subs = v->sub10;
      v->nsubs = 10;
      for (j = 0; j < v->nsubs; j++)
            v->subs[j] = NULL;
      v->nfa = NULL;
      v->cm = NULL;
      v->nlcolor = COLORLESS;
      v->wordchrs = NULL;
      v->tree = NULL;
      v->treechain = NULL;
      v->treefree = NULL;
      v->cv = NULL;
      v->cv2 = NULL;
      v->mcces = NULL;
      v->lacons = NULL;
      v->nlacons = 0;
      re->re_magic = REMAGIC;
      re->re_info = 0;        /* bits get set during parse */
      re->re_csize = sizeof(chr);
      re->re_guts = NULL;
      re->re_fns = VS(&functions);

      /* more complex setup, malloced things */
      re->re_guts = VS(MALLOC(sizeof(struct guts)));
      if (re->re_guts == NULL)
            return freev(v, REG_ESPACE);
      g = (struct guts *)re->re_guts;
      g->tree = NULL;
      initcm(v, &g->cmap);
      v->cm = &g->cmap;
      g->lacons = NULL;
      g->nlacons = 0;
      ZAPCNFA(g->search);
      v->nfa = newnfa(v, v->cm, (struct nfa *)NULL);
      CNOERR();
      v->cv = newcvec(100, 20, 10);
      if (v->cv == NULL)
            return freev(v, REG_ESPACE);
      i = nmcces(v);
      if (i > 0) {
            v->mcces = newcvec(nleaders(v), 0, i);
            CNOERR();
            v->mcces = allmcces(v, v->mcces);
            leaders(v, v->mcces);
            addmcce(v->mcces, (chr *)NULL, (chr *)NULL);    /* dummy */
      }
      CNOERR();

      /* parsing */
      lexstart(v);                  /* also handles prefixes */
      if ((v->cflags&REG_NLSTOP) || (v->cflags&REG_NLANCH)) {
            /* assign newline a unique color */
            v->nlcolor = subcolor(v->cm, newline());
            okcolors(v->nfa, v->cm);
      }
      CNOERR();
      v->tree = parse(v, EOS, PLAIN, v->nfa->init, v->nfa->final);
      assert(SEE(EOS));       /* even if error; ISERR() => SEE(EOS) */
      CNOERR();
      assert(v->tree != NULL);

      /* finish setup of nfa and its subre tree */
      specialcolors(v->nfa);
      CNOERR();
      if (debug != NULL) {
            fprintf(debug, "\n\n\n========= RAW ==========\n");
            dumpnfa(v->nfa, debug);
            dumpst(v->tree, debug, 1);
      }
      optst(v, v->tree);
      v->ntree = numst(v->tree, 1);
      markst(v->tree);
      cleanst(v);
      if (debug != NULL) {
            fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
            dumpst(v->tree, debug, 1);
      }

      /* build compacted NFAs for tree and lacons */
      re->re_info |= nfatree(v, v->tree, debug);
      CNOERR();
      assert(v->nlacons == 0 || v->lacons != NULL);
      for (i = 1; i < v->nlacons; i++) {
            if (debug != NULL)
                  fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
            nfanode(v, &v->lacons[i], debug);
      }
      CNOERR();
      if (v->tree->flags&SHORTER)
            NOTE(REG_USHORTEST);

      /* build compacted NFAs for tree, lacons, fast search */
      if (debug != NULL)
            fprintf(debug, "\n\n\n========= SEARCH ==========\n");
      /* can sacrifice main NFA now, so use it as work area */
      (DISCARD)optimize(v->nfa, debug);
      CNOERR();
      makesearch(v, v->nfa);
      CNOERR();
      compact(v->nfa, &g->search);
      CNOERR();

      /* looks okay, package it up */
      re->re_nsub = v->nsubexp;
      v->re = NULL;                 /* freev no longer frees re */
      g->magic = GUTSMAGIC;
      g->cflags = v->cflags;
      g->info = re->re_info;
      g->nsub = re->re_nsub;
      g->tree = v->tree;
      v->tree = NULL;
      g->ntree = v->ntree;
      g->compare = (v->cflags&REG_ICASE) ? casecmp : cmp;
      g->lacons = v->lacons;
      v->lacons = NULL;
      g->nlacons = v->nlacons;

      if (flags&REG_DUMP)
            dump(re, stdout);

      assert(v->err == 0);
      return freev(v, 0);
}

/*
 - moresubs - enlarge subRE vector
 ^ static VOID moresubs(struct vars *, int);
 */
static VOID
moresubs(v, wanted)
struct vars *v;
int wanted;             /* want enough room for this one */
{
      struct subre **p;
      size_t n;

      assert(wanted > 0 && (size_t)wanted >= v->nsubs);
      n = (size_t)wanted * 3 / 2 + 1;
      if (v->subs == v->sub10) {
            p = (struct subre **)MALLOC(n * sizeof(struct subre *));
            if (p != NULL)
                  memcpy(VS(p), VS(v->subs),
                              v->nsubs * sizeof(struct subre *));
      } else
            p = (struct subre **)REALLOC(v->subs, n*sizeof(struct subre *));
      if (p == NULL) {
            ERR(REG_ESPACE);
            return;
      }
      v->subs = p;
      for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++)
            *p = NULL;
      assert(v->nsubs == n);
      assert((size_t)wanted < v->nsubs);
}

/*
 - freev - free vars struct's substructures where necessary
 * Optionally does error-number setting, and always returns error code
 * (if any), to make error-handling code terser.
 ^ static int freev(struct vars *, int);
 */
static int
freev(v, err)
struct vars *v;
int err;
{
      if (v->re != NULL)
            rfree(v->re);
      if (v->subs != v->sub10)
            FREE(v->subs);
      if (v->nfa != NULL)
            freenfa(v->nfa);
      if (v->tree != NULL)
            freesubre(v, v->tree);
      if (v->treechain != NULL)
            cleanst(v);
      if (v->cv != NULL)
            freecvec(v->cv);
      if (v->cv2 != NULL)
            freecvec(v->cv2);
      if (v->mcces != NULL)
            freecvec(v->mcces);
      if (v->lacons != NULL)
            freelacons(v->lacons, v->nlacons);
      ERR(err);               /* nop if err==0 */

      return v->err;
}

/*
 - makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
 * NFA must have been optimize()d already.
 ^ static VOID makesearch(struct vars *, struct nfa *);
 */
static VOID
makesearch(v, nfa)
struct vars *v;
struct nfa *nfa;
{
      struct arc *a;
      struct arc *b;
      struct state *pre = nfa->pre;
      struct state *s;
      struct state *s2;
      struct state *slist;

      /* no loops are needed if it's anchored */
      for (a = pre->outs; a != NULL; a = a->outchain) {
            assert(a->type == PLAIN);
            if (a->co != nfa->bos[0] && a->co != nfa->bos[1])
                  break;
      }
      if (a != NULL) {
            /* add implicit .* in front */
            rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre);

            /* and ^* and \A* too -- not always necessary, but harmless */
            newarc(nfa, PLAIN, nfa->bos[0], pre, pre);
            newarc(nfa, PLAIN, nfa->bos[1], pre, pre);
      }

      /*
       * Now here's the subtle part.  Because many REs have no lookback
       * constraints, often knowing when you were in the pre state tells
       * you little; it's the next state(s) that are informative.  But
       * some of them may have other inarcs, i.e. it may be possible to
       * make actual progress and then return to one of them.  We must
       * de-optimize such cases, splitting each such state into progress
       * and no-progress states.
       */

      /* first, make a list of the states */
      slist = NULL;
      for (a = pre->outs; a != NULL; a = a->outchain) {
            s = a->to;
            for (b = s->ins; b != NULL; b = b->inchain)
                  if (b->from != pre)
                        break;
            if (b != NULL) {        /* must be split */
                  if (s->tmp == NULL) {  /* if not already in the list */
                                         /* (fixes bugs 505048, 230589, */
                                         /* 840258, 504785) */
                        s->tmp = slist;
                        slist = s;
                  }
            }
      }

      /* do the splits */
      for (s = slist; s != NULL; s = s2) {
            s2 = newstate(nfa);
            copyouts(nfa, s, s2);
            for (a = s->ins; a != NULL; a = b) {
                  b = a->inchain;
                  if (a->from != pre) {
                        cparc(nfa, a, a->from, s2);
                        freearc(nfa, a);
                  }
            }
            s2 = s->tmp;
            s->tmp = NULL;          /* clean up while we're at it */
      }
}

/*
 - parse - parse an RE
 * This is actually just the top level, which parses a bunch of branches
 * tied together with '|'.  They appear in the tree as the left children
 * of a chain of '|' subres.
 ^ static struct subre *parse(struct vars *, int, int, struct state *,
 ^    struct state *);
 */
static struct subre *
parse(v, stopper, type, init, final)
struct vars *v;
int stopper;                  /* EOS or ')' */
int type;               /* LACON (lookahead subRE) or PLAIN */
struct state *init;           /* initial state */
struct state *final;          /* final state */
{
      struct state *left;     /* scaffolding for branch */
      struct state *right;
      struct subre *branches; /* top level */
      struct subre *branch;   /* current branch */
      struct subre *t;  /* temporary */
      int firstbranch;  /* is this the first branch? */

      assert(stopper == ')' || stopper == EOS);

      branches = subre(v, '|', LONGER, init, final);
      NOERRN();
      branch = branches;
      firstbranch = 1;
      do {  /* a branch */
            if (!firstbranch) {
                  /* need a place to hang it */
                  branch->right = subre(v, '|', LONGER, init, final);
                  NOERRN();
                  branch = branch->right;
            }
            firstbranch = 0;
            left = newstate(v->nfa);
            right = newstate(v->nfa);
            NOERRN();
            EMPTYARC(init, left);
            EMPTYARC(right, final);
            NOERRN();
            branch->left = parsebranch(v, stopper, type, left, right, 0);
            NOERRN();
            branch->flags |= UP(branch->flags | branch->left->flags);
            if ((branch->flags &~ branches->flags) != 0)    /* new flags */
                  for (t = branches; t != branch; t = t->right)
                        t->flags |= branch->flags;
      } while (EAT('|'));
      assert(SEE(stopper) || SEE(EOS));

      if (!SEE(stopper)) {
            assert(stopper == ')' && SEE(EOS));
            ERR(REG_EPAREN);
      }

      /* optimize out simple cases */
      if (branch == branches) {     /* only one branch */
            assert(branch->right == NULL);
            t = branch->left;
            branch->left = NULL;
            freesubre(v, branches);
            branches = t;
      } else if (!MESSY(branches->flags)) {     /* no interesting innards */
            freesubre(v, branches->left);
            branches->left = NULL;
            freesubre(v, branches->right);
            branches->right = NULL;
            branches->op = '=';
      }

      return branches;
}

/*
 - parsebranch - parse one branch of an RE
 * This mostly manages concatenation, working closely with parseqatom().
 * Concatenated things are bundled up as much as possible, with separate
 * ',' nodes introduced only when necessary due to substructure.
 ^ static struct subre *parsebranch(struct vars *, int, int, struct state *,
 ^    struct state *, int);
 */
static struct subre *
parsebranch(v, stopper, type, left, right, partial)
struct vars *v;
int stopper;                  /* EOS or ')' */
int type;               /* LACON (lookahead subRE) or PLAIN */
struct state *left;           /* leftmost state */
struct state *right;          /* rightmost state */
int partial;                  /* is this only part of a branch? */
{
      struct state *lp; /* left end of current construct */
      int seencontent;  /* is there anything in this branch yet? */
      struct subre *t;

      lp = left;
      seencontent = 0;
      t = subre(v, '=', 0, left, right);  /* op '=' is tentative */
      NOERRN();
      while (!SEE('|') && !SEE(stopper) && !SEE(EOS)) {
            if (seencontent) {      /* implicit concat operator */
                  lp = newstate(v->nfa);
                  NOERRN();
                  moveins(v->nfa, right, lp);
            }
            seencontent = 1;

            /* NB, recursion in parseqatom() may swallow rest of branch */
            parseqatom(v, stopper, type, lp, right, t);
      }

      if (!seencontent) {           /* empty branch */
            if (!partial)
                  NOTE(REG_UUNSPEC);
            assert(lp == left);
            EMPTYARC(left, right);
      }

      return t;
}

/*
 - parseqatom - parse one quantified atom or constraint of an RE
 * The bookkeeping near the end cooperates very closely with parsebranch();
 * in particular, it contains a recursion that can involve parsing the rest
 * of the branch, making this function's name somewhat inaccurate.
 ^ static VOID parseqatom(struct vars *, int, int, struct state *,
 ^    struct state *, struct subre *);
 */
static VOID
parseqatom(v, stopper, type, lp, rp, top)
struct vars *v;
int stopper;                  /* EOS or ')' */
int type;               /* LACON (lookahead subRE) or PLAIN */
struct state *lp;       /* left state to hang it on */
struct state *rp;       /* right state to hang it on */
struct subre *top;            /* subtree top */
{
      struct state *s;  /* temporaries for new states */
      struct state *s2;
#     define      ARCV(t, val)      newarc(v->nfa, t, val, lp, rp)
      int m, n;
      struct subre *atom;     /* atom's subtree */
      struct subre *t;
      int cap;          /* capturing parens? */
      int pos;          /* positive lookahead? */
      int subno;        /* capturing-parens or backref number */
      int atomtype;
      int qprefer;            /* quantifier short/long preference */
      int f;
      struct subre **atomp;   /* where the pointer to atom is */

      /* initial bookkeeping */
      atom = NULL;
      assert(lp->nouts == 0); /* must string new code */
      assert(rp->nins == 0);  /*  between lp and rp */
      subno = 0;        /* just to shut lint up */

      /* an atom or constraint... */
      atomtype = v->nexttype;
      switch (atomtype) {
      /* first, constraints, which end by returning */
      case '^':
            ARCV('^', 1);
            if (v->cflags&REG_NLANCH)
                  ARCV(BEHIND, v->nlcolor);
            NEXT();
            return;
            break;
      case '$':
            ARCV('$', 1);
            if (v->cflags&REG_NLANCH)
                  ARCV(AHEAD, v->nlcolor);
            NEXT();
            return;
            break;
      case SBEGIN:
            ARCV('^', 1);     /* BOL */
            ARCV('^', 0);     /* or BOS */
            NEXT();
            return;
            break;
      case SEND:
            ARCV('$', 1);     /* EOL */
            ARCV('$', 0);     /* or EOS */
            NEXT();
            return;
            break;
      case '<':
            wordchrs(v);      /* does NEXT() */
            s = newstate(v->nfa);
            NOERR();
            nonword(v, BEHIND, lp, s);
            word(v, AHEAD, s, rp);
            return;
            break;
      case '>':
            wordchrs(v);      /* does NEXT() */
            s = newstate(v->nfa);
            NOERR();
            word(v, BEHIND, lp, s);
            nonword(v, AHEAD, s, rp);
            return;
            break;
      case WBDRY:
            wordchrs(v);      /* does NEXT() */
            s = newstate(v->nfa);
            NOERR();
            nonword(v, BEHIND, lp, s);
            word(v, AHEAD, s, rp);
            s = newstate(v->nfa);
            NOERR();
            word(v, BEHIND, lp, s);
            nonword(v, AHEAD, s, rp);
            return;
            break;
      case NWBDRY:
            wordchrs(v);      /* does NEXT() */
            s = newstate(v->nfa);
            NOERR();
            word(v, BEHIND, lp, s);
            word(v, AHEAD, s, rp);
            s = newstate(v->nfa);
            NOERR();
            nonword(v, BEHIND, lp, s);
            nonword(v, AHEAD, s, rp);
            return;
            break;
      case LACON: /* lookahead constraint */
            pos = v->nextvalue;
            NEXT();
            s = newstate(v->nfa);
            s2 = newstate(v->nfa);
            NOERR();
            t = parse(v, ')', LACON, s, s2);
            freesubre(v, t);  /* internal structure irrelevant */
            assert(SEE(')') || ISERR());
            NEXT();
            n = newlacon(v, s, s2, pos);
            NOERR();
            ARCV(LACON, n);
            return;
            break;
      /* then errors, to get them out of the way */
      case '*':
      case '+':
      case '?':
      case '{':
            ERR(REG_BADRPT);
            return;
            break;
      default:
            ERR(REG_ASSERT);
            return;
            break;
      /* then plain characters, and minor variants on that theme */
      case ')':         /* unbalanced paren */
            if ((v->cflags&REG_ADVANCED) != REG_EXTENDED) {
                  ERR(REG_EPAREN);
                  return;
            }
            /* legal in EREs due to specification botch */
            NOTE(REG_UPBOTCH);
            /* fallthrough into case PLAIN */
      case PLAIN:
            onechr(v, v->nextvalue, lp, rp);
            okcolors(v->nfa, v->cm);
            NOERR();
            NEXT();
            break;
      case '[':
            if (v->nextvalue == 1)
                  bracket(v, lp, rp);
            else
                  cbracket(v, lp, rp);
            assert(SEE(']') || ISERR());
            NEXT();
            break;
      case '.':
            rainbow(v->nfa, v->cm, PLAIN,
                        (v->cflags&REG_NLSTOP) ? v->nlcolor : COLORLESS,
                        lp, rp);
            NEXT();
            break;
      /* and finally the ugly stuff */
      case '(':   /* value flags as capturing or non */
            cap = (type == LACON) ? 0 : v->nextvalue;
            if (cap) {
                  v->nsubexp++;
                  subno = v->nsubexp;
                  if ((size_t)subno >= v->nsubs)
                        moresubs(v, subno);
                  assert((size_t)subno < v->nsubs);
            } else
                  atomtype = PLAIN; /* something that's not '(' */
            NEXT();
            /* need new endpoints because tree will contain pointers */
            s = newstate(v->nfa);
            s2 = newstate(v->nfa);
            NOERR();
            EMPTYARC(lp, s);
            EMPTYARC(s2, rp);
            NOERR();
            atom = parse(v, ')', PLAIN, s, s2);
            assert(SEE(')') || ISERR());
            NEXT();
            NOERR();
            if (cap) {
                  v->subs[subno] = atom;
                  t = subre(v, '(', atom->flags|CAP, lp, rp);
                  NOERR();
                  t->subno = subno;
                  t->left = atom;
                  atom = t;
            }
            /* postpone everything else pending possible {0} */
            break;
      case BACKREF:     /* the Feature From The Black Lagoon */
            INSIST(type != LACON, REG_ESUBREG);
            INSIST(v->nextvalue < v->nsubs, REG_ESUBREG);
            INSIST(v->subs[v->nextvalue] != NULL, REG_ESUBREG);
            NOERR();
            assert(v->nextvalue > 0);
            atom = subre(v, 'b', BACKR, lp, rp);
            subno = v->nextvalue;
            atom->subno = subno;
            EMPTYARC(lp, rp); /* temporarily, so there's something */
            NEXT();
            break;
      }

      /* ...and an atom may be followed by a quantifier */
      switch (v->nexttype) {
      case '*':
            m = 0;
            n = INFINITY;
            qprefer = (v->nextvalue) ? LONGER : SHORTER;
            NEXT();
            break;
      case '+':
            m = 1;
            n = INFINITY;
            qprefer = (v->nextvalue) ? LONGER : SHORTER;
            NEXT();
            break;
      case '?':
            m = 0;
            n = 1;
            qprefer = (v->nextvalue) ? LONGER : SHORTER;
            NEXT();
            break;
      case '{':
            NEXT();
            m = scannum(v);
            if (EAT(',')) {
                  if (SEE(DIGIT))
                        n = scannum(v);
                  else
                        n = INFINITY;
                  if (m > n) {
                        ERR(REG_BADBR);
                        return;
                  }
                  /* {m,n} exercises preference, even if it's {m,m} */
                  qprefer = (v->nextvalue) ? LONGER : SHORTER;
            } else {
                  n = m;
                  /* {m} passes operand's preference through */
                  qprefer = 0;
            }
            if (!SEE('}')) {  /* catches errors too */
                  ERR(REG_BADBR);
                  return;
            }
            NEXT();
            break;
      default:          /* no quantifier */
            m = n = 1;
            qprefer = 0;
            break;
      }

      /* annoying special case:  {0} or {0,0} cancels everything */
      if (m == 0 && n == 0) {
            if (atom != NULL)
                  freesubre(v, atom);
            if (atomtype == '(')
                  v->subs[subno] = NULL;
            delsub(v->nfa, lp, rp);
            EMPTYARC(lp, rp);
            return;
      }

      /* if not a messy case, avoid hard part */
      assert(!MESSY(top->flags));
      f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0);
      if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f))) {
            if (!(m == 1 && n == 1))
                  repeat(v, lp, rp, m, n);
            if (atom != NULL)
                  freesubre(v, atom);
            top->flags = f;
            return;
      }

      /*
       * hard part:  something messy
       * That is, capturing parens, back reference, short/long clash, or
       * an atom with substructure containing one of those.
       */

      /* now we'll need a subre for the contents even if they're boring */
      if (atom == NULL) {
            atom = subre(v, '=', 0, lp, rp);
            NOERR();
      }

      /*
       * prepare a general-purpose state skeleton
       *
       *    ---> [s] ---prefix---> [begin] ---atom---> [end] ----rest---> [rp]
       *   /                                            /
       * [lp] ----> [s2] ----bypass---------------------
       *
       * where bypass is an empty, and prefix is some repetitions of atom
       */
      s = newstate(v->nfa);         /* first, new endpoints for the atom */
      s2 = newstate(v->nfa);
      NOERR();
      moveouts(v->nfa, lp, s);
      moveins(v->nfa, rp, s2);
      NOERR();
      atom->begin = s;
      atom->end = s2;
      s = newstate(v->nfa);         /* and spots for prefix and bypass */
      s2 = newstate(v->nfa);
      NOERR();
      EMPTYARC(lp, s);
      EMPTYARC(lp, s2);
      NOERR();

      /* break remaining subRE into x{...} and what follows */
      t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp);
      t->left = atom;
      atomp = &t->left;
      /* here we should recurse... but we must postpone that to the end */

      /* split top into prefix and remaining */
      assert(top->op == '=' && top->left == NULL && top->right == NULL);
      top->left = subre(v, '=', top->flags, top->begin, lp);
      top->op = '.';
      top->right = t;

      /* if it's a backref, now is the time to replicate the subNFA */
      if (atomtype == BACKREF) {
            assert(atom->begin->nouts == 1);    /* just the EMPTY */
            delsub(v->nfa, atom->begin, atom->end);
            assert(v->subs[subno] != NULL);
            /* and here's why the recursion got postponed:  it must */
            /* wait until the skeleton is filled in, because it may */
            /* hit a backref that wants to copy the filled-in skeleton */
            dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end,
                                    atom->begin, atom->end);
            NOERR();
      }

      /* it's quantifier time; first, turn x{0,...} into x{1,...}|empty */
      if (m == 0) {
            EMPTYARC(s2, atom->end);            /* the bypass */
            assert(PREF(qprefer) != 0);
            f = COMBINE(qprefer, atom->flags);
            t = subre(v, '|', f, lp, atom->end);
            NOERR();
            t->left = atom;
            t->right = subre(v, '|', PREF(f), s2, atom->end);
            NOERR();
            t->right->left = subre(v, '=', 0, s2, atom->end);
            NOERR();
            *atomp = t;
            atomp = &t->left;
            m = 1;
      }

      /* deal with the rest of the quantifier */
      if (atomtype == BACKREF) {
            /* special case:  backrefs have internal quantifiers */
            EMPTYARC(s, atom->begin);     /* empty prefix */
            /* just stuff everything into atom */
            repeat(v, atom->begin, atom->end, m, n);
            atom->min = (short)m;
            atom->max = (short)n;
            atom->flags |= COMBINE(qprefer, atom->flags);
      } else if (m == 1 && n == 1) {
            /* no/vacuous quantifier:  done */
            EMPTYARC(s, atom->begin);     /* empty prefix */
      } else {
            /* turn x{m,n} into x{m-1,n-1}x, with capturing */
            /*  parens in only second x */
            dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin);
            assert(m >= 1 && m != INFINITY && n >= 1);
            repeat(v, s, atom->begin, m-1, (n == INFINITY) ? n : n-1);
            f = COMBINE(qprefer, atom->flags);
            t = subre(v, '.', f, s, atom->end); /* prefix and atom */
            NOERR();
            t->left = subre(v, '=', PREF(f), s, atom->begin);
            NOERR();
            t->right = atom;
            *atomp = t;
      }

      /* and finally, look after that postponed recursion */
      t = top->right;
      if (!(SEE('|') || SEE(stopper) || SEE(EOS)))
            t->right = parsebranch(v, stopper, type, atom->end, rp, 1);
      else {
            EMPTYARC(atom->end, rp);
            t->right = subre(v, '=', 0, atom->end, rp);
      }
      assert(SEE('|') || SEE(stopper) || SEE(EOS));
      t->flags |= COMBINE(t->flags, t->right->flags);
      top->flags |= COMBINE(top->flags, t->flags);
}

/*
 - nonword - generate arcs for non-word-character ahead or behind
 ^ static VOID nonword(struct vars *, int, struct state *, struct state *);
 */
static VOID
nonword(v, dir, lp, rp)
struct vars *v;
int dir;                /* AHEAD or BEHIND */
struct state *lp;
struct state *rp;
{
      int anchor = (dir == AHEAD) ? '$' : '^';

      assert(dir == AHEAD || dir == BEHIND);
      newarc(v->nfa, anchor, 1, lp, rp);
      newarc(v->nfa, anchor, 0, lp, rp);
      colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp);
      /* (no need for special attention to \n) */
}

/*
 - word - generate arcs for word character ahead or behind
 ^ static VOID word(struct vars *, int, struct state *, struct state *);
 */
static VOID
word(v, dir, lp, rp)
struct vars *v;
int dir;                /* AHEAD or BEHIND */
struct state *lp;
struct state *rp;
{
      assert(dir == AHEAD || dir == BEHIND);
      cloneouts(v->nfa, v->wordchrs, lp, rp, dir);
      /* (no need for special attention to \n) */
}

/*
 - scannum - scan a number
 ^ static int scannum(struct vars *);
 */
static int              /* value, <= DUPMAX */
scannum(v)
struct vars *v;
{
      int n = 0;

      while (SEE(DIGIT) && n < DUPMAX) {
            n = n*10 + v->nextvalue;
            NEXT();
      }
      if (SEE(DIGIT) || n > DUPMAX) {
            ERR(REG_BADBR);
            return 0;
      }
      return n;
}

/*
 - repeat - replicate subNFA for quantifiers
 * The duplication sequences used here are chosen carefully so that any
 * pointers starting out pointing into the subexpression end up pointing into
 * the last occurrence.  (Note that it may not be strung between the same
 * left and right end states, however!)  This used to be important for the
 * subRE tree, although the important bits are now handled by the in-line
 * code in parse(), and when this is called, it doesn't matter any more.
 ^ static VOID repeat(struct vars *, struct state *, struct state *, int, int);
 */
static VOID
repeat(v, lp, rp, m, n)
struct vars *v;
struct state *lp;
struct state *rp;
int m;
int n;
{
#     define      SOME  2
#     define      INF   3
#     define      PAIR(x, y)  ((x)*4 + (y))
#     define      REDUCE(x)   ( ((x) == INFINITY) ? INF : (((x) > 1) ? SOME : (x)) )
      CONST int rm = REDUCE(m);
      CONST int rn = REDUCE(n);
      struct state *s;
      struct state *s2;

      switch (PAIR(rm, rn)) {
      case PAIR(0, 0):        /* empty string */
            delsub(v->nfa, lp, rp);
            EMPTYARC(lp, rp);
            break;
      case PAIR(0, 1):        /* do as x| */
            EMPTYARC(lp, rp);
            break;
      case PAIR(0, SOME):           /* do as x{1,n}| */
            repeat(v, lp, rp, 1, n);
            NOERR();
            EMPTYARC(lp, rp);
            break;
      case PAIR(0, INF):            /* loop x around */
            s = newstate(v->nfa);
            NOERR();
            moveouts(v->nfa, lp, s);
            moveins(v->nfa, rp, s);
            EMPTYARC(lp, s);
            EMPTYARC(s, rp);
            break;
      case PAIR(1, 1):        /* no action required */
            break;
      case PAIR(1, SOME):           /* do as x{0,n-1}x = (x{1,n-1}|)x */
            s = newstate(v->nfa);
            NOERR();
            moveouts(v->nfa, lp, s);
            dupnfa(v->nfa, s, rp, lp, s);
            NOERR();
            repeat(v, lp, s, 1, n-1);
            NOERR();
            EMPTYARC(lp, s);
            break;
      case PAIR(1, INF):            /* add loopback arc */
            s = newstate(v->nfa);
            s2 = newstate(v->nfa);
            NOERR();
            moveouts(v->nfa, lp, s);
            moveins(v->nfa, rp, s2);
            EMPTYARC(lp, s);
            EMPTYARC(s2, rp);
            EMPTYARC(s2, s);
            break;
      case PAIR(SOME, SOME):        /* do as x{m-1,n-1}x */
            s = newstate(v->nfa);
            NOERR();
            moveouts(v->nfa, lp, s);
            dupnfa(v->nfa, s, rp, lp, s);
            NOERR();
            repeat(v, lp, s, m-1, n-1);
            break;
      case PAIR(SOME, INF):         /* do as x{m-1,}x */
            s = newstate(v->nfa);
            NOERR();
            moveouts(v->nfa, lp, s);
            dupnfa(v->nfa, s, rp, lp, s);
            NOERR();
            repeat(v, lp, s, m-1, n);
            break;
      default:
            ERR(REG_ASSERT);
            break;
      }
}

/*
 - bracket - handle non-complemented bracket expression
 * Also called from cbracket for complemented bracket expressions.
 ^ static VOID bracket(struct vars *, struct state *, struct state *);
 */
static VOID
bracket(v, lp, rp)
struct vars *v;
struct state *lp;
struct state *rp;
{
      assert(SEE('['));
      NEXT();
      while (!SEE(']') && !SEE(EOS))
            brackpart(v, lp, rp);
      assert(SEE(']') || ISERR());
      okcolors(v->nfa, v->cm);
}

/*
 - cbracket - handle complemented bracket expression
 * We do it by calling bracket() with dummy endpoints, and then complementing
 * the result.  The alternative would be to invoke rainbow(), and then delete
 * arcs as the b.e. is seen... but that gets messy.
 ^ static VOID cbracket(struct vars *, struct state *, struct state *);
 */
static VOID
cbracket(v, lp, rp)
struct vars *v;
struct state *lp;
struct state *rp;
{
      struct state *left = newstate(v->nfa);
      struct state *right = newstate(v->nfa);
      struct state *s;
      struct arc *a;                /* arc from lp */
      struct arc *ba;               /* arc from left, from bracket() */
      struct arc *pa;               /* MCCE-prototype arc */
      color co;
      chr *p;
      int i;

      NOERR();
      bracket(v, left, right);
      if (v->cflags&REG_NLSTOP)
            newarc(v->nfa, PLAIN, v->nlcolor, left, right);
      NOERR();

      assert(lp->nouts == 0);       /* all outarcs will be ours */

      /* easy part of complementing */
      colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
      NOERR();
      if (v->mcces == NULL) {       /* no MCCEs -- we're done */
            dropstate(v->nfa, left);
            assert(right->nins == 0);
            freestate(v->nfa, right);
            return;
      }

      /* but complementing gets messy in the presence of MCCEs... */
      NOTE(REG_ULOCALE);
      for (p = v->mcces->chrs, i = v->mcces->nchrs; i > 0; p++, i--) {
            co = GETCOLOR(v->cm, *p);
            a = findarc(lp, PLAIN, co);
            ba = findarc(left, PLAIN, co);
            if (ba == NULL) {
                  assert(a != NULL);
                  freearc(v->nfa, a);
            } else {
                  assert(a == NULL);
            }
            s = newstate(v->nfa);
            NOERR();
            newarc(v->nfa, PLAIN, co, lp, s);
            NOERR();
            pa = findarc(v->mccepbegin, PLAIN, co);
            assert(pa != NULL);
            if (ba == NULL) { /* easy case, need all of them */
                  cloneouts(v->nfa, pa->to, s, rp, PLAIN);
                  newarc(v->nfa, '$', 1, s, rp);
                  newarc(v->nfa, '$', 0, s, rp);
                  colorcomplement(v->nfa, v->cm, AHEAD, pa->to, s, rp);
            } else {          /* must be selective */
                  if (findarc(ba->to, '$', 1) == NULL) {
                        newarc(v->nfa, '$', 1, s, rp);
                        newarc(v->nfa, '$', 0, s, rp);
                        colorcomplement(v->nfa, v->cm, AHEAD, pa->to,
                                                       s, rp);
                  }
                  for (pa = pa->to->outs; pa != NULL; pa = pa->outchain)
                        if (findarc(ba->to, PLAIN, pa->co) == NULL)
                              newarc(v->nfa, PLAIN, pa->co, s, rp);
                  if (s->nouts == 0)      /* limit of selectivity: none */
                        dropstate(v->nfa, s);   /* frees arc too */
            }
            NOERR();
      }

      delsub(v->nfa, left, right);
      assert(left->nouts == 0);
      freestate(v->nfa, left);
      assert(right->nins == 0);
      freestate(v->nfa, right);
}
                  
/*
 - brackpart - handle one item (or range) within a bracket expression
 ^ static VOID brackpart(struct vars *, struct state *, struct state *);
 */
static VOID
brackpart(v, lp, rp)
struct vars *v;
struct state *lp;
struct state *rp;
{
      celt startc;
      celt endc;
      struct cvec *cv;
      chr *startp;
      chr *endp;
      chr c[1];

      /* parse something, get rid of special cases, take shortcuts */
      switch (v->nexttype) {
      case RANGE:             /* a-b-c or other botch */
            ERR(REG_ERANGE);
            return;
            break;
      case PLAIN:
            c[0] = v->nextvalue;
            NEXT();
            /* shortcut for ordinary chr (not range, not MCCE leader) */
            if (!SEE(RANGE) && !ISCELEADER(v, c[0])) {
                  onechr(v, c[0], lp, rp);
                  return;
            }
            startc = element(v, c, c+1);
            NOERR();
            break;
      case COLLEL:
            startp = v->now;
            endp = scanplain(v);
            INSIST(startp < endp, REG_ECOLLATE);
            NOERR();
            startc = element(v, startp, endp);
            NOERR();
            break;
      case ECLASS:
            startp = v->now;
            endp = scanplain(v);
            INSIST(startp < endp, REG_ECOLLATE);
            NOERR();
            startc = element(v, startp, endp);
            NOERR();
            cv = eclass(v, startc, (v->cflags&REG_ICASE));
            NOERR();
            dovec(v, cv, lp, rp);
            return;
            break;
      case CCLASS:
            startp = v->now;
            endp = scanplain(v);
            INSIST(startp < endp, REG_ECTYPE);
            NOERR();
            cv = cclass(v, startp, endp, (v->cflags&REG_ICASE));
            NOERR();
            dovec(v, cv, lp, rp);
            return;
            break;
      default:
            ERR(REG_ASSERT);
            return;
            break;
      }

      if (SEE(RANGE)) {
            NEXT();
            switch (v->nexttype) {
            case PLAIN:
            case RANGE:
                  c[0] = v->nextvalue;
                  NEXT();
                  endc = element(v, c, c+1);
                  NOERR();
                  break;
            case COLLEL:
                  startp = v->now;
                  endp = scanplain(v);
                  INSIST(startp < endp, REG_ECOLLATE);
                  NOERR();
                  endc = element(v, startp, endp);
                  NOERR();
                  break;
            default:
                  ERR(REG_ERANGE);
                  return;
                  break;
            }
      } else
            endc = startc;

      /*
       * Ranges are unportable.  Actually, standard C does
       * guarantee that digits are contiguous, but making
       * that an exception is just too complicated.
       */
      if (startc != endc)
            NOTE(REG_UUNPORT);
      cv = range(v, startc, endc, (v->cflags&REG_ICASE));
      NOERR();
      dovec(v, cv, lp, rp);
}

/*
 - scanplain - scan PLAIN contents of [. etc.
 * Certain bits of trickery in lex.c know that this code does not try
 * to look past the final bracket of the [. etc.
 ^ static chr *scanplain(struct vars *);
 */
static chr *                  /* just after end of sequence */
scanplain(v)
struct vars *v;
{
      chr *endp;

      assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
      NEXT();

      endp = v->now;
      while (SEE(PLAIN)) {
            endp = v->now;
            NEXT();
      }

      assert(SEE(END) || ISERR());
      NEXT();

      return endp;
}

/*
 - leaders - process a cvec of collating elements to also include leaders
 * Also gives all characters involved their own colors, which is almost
 * certainly necessary, and sets up little disconnected subNFA.
 ^ static VOID leaders(struct vars *, struct cvec *);
 */
static VOID
leaders(v, cv)
struct vars *v;
struct cvec *cv;
{
      int mcce;
      chr *p;
      chr leader;
      struct state *s;
      struct arc *a;

      v->mccepbegin = newstate(v->nfa);
      v->mccepend = newstate(v->nfa);
      NOERR();

      for (mcce = 0; mcce < cv->nmcces; mcce++) {
            p = cv->mcces[mcce];
            leader = *p;
            if (!haschr(cv, leader)) {
                  addchr(cv, leader);
                  s = newstate(v->nfa);
                  newarc(v->nfa, PLAIN, subcolor(v->cm, leader),
                                          v->mccepbegin, s);
                  okcolors(v->nfa, v->cm);
            } else {
                  a = findarc(v->mccepbegin, PLAIN,
                                    GETCOLOR(v->cm, leader));
                  assert(a != NULL);
                  s = a->to;
                  assert(s != v->mccepend);
            }
            p++;
            assert(*p != 0 && *(p+1) == 0);     /* only 2-char MCCEs for now */
            newarc(v->nfa, PLAIN, subcolor(v->cm, *p), s, v->mccepend);
            okcolors(v->nfa, v->cm);
      }
}

/*
 - onechr - fill in arcs for a plain character, and possible case complements
 * This is mostly a shortcut for efficient handling of the common case.
 ^ static VOID onechr(struct vars *, pchr, struct state *, struct state *);
 */
static VOID
onechr(v, c, lp, rp)
struct vars *v;
pchr c;
struct state *lp;
struct state *rp;
{
      if (!(v->cflags&REG_ICASE)) {
            newarc(v->nfa, PLAIN, subcolor(v->cm, c), lp, rp);
            return;
      }

      /* rats, need general case anyway... */
      dovec(v, allcases(v, c), lp, rp);
}

/*
 - dovec - fill in arcs for each element of a cvec
 * This one has to handle the messy cases, like MCCEs and MCCE leaders.
 ^ static VOID dovec(struct vars *, struct cvec *, struct state *,
 ^    struct state *);
 */
static VOID
dovec(v, cv, lp, rp)
struct vars *v;
struct cvec *cv;
struct state *lp;
struct state *rp;
{
      chr ch, from, to;
      celt ce;
      chr *p;
      int i;
      color co;
      struct cvec *leads;
      struct arc *a;
      struct arc *pa;         /* arc in prototype */
      struct state *s;
      struct state *ps; /* state in prototype */

      /* need a place to store leaders, if any */
      if (nmcces(v) > 0) {
            assert(v->mcces != NULL);
            if (v->cv2 == NULL || v->cv2->nchrs < v->mcces->nchrs) {
                  if (v->cv2 != NULL)
                        free(v->cv2);
                  v->cv2 = newcvec(v->mcces->nchrs, 0, v->mcces->nmcces);
                  NOERR();
                  leads = v->cv2;
            } else
                  leads = clearcvec(v->cv2);
      } else
            leads = NULL;

      /* first, get the ordinary characters out of the way */
      for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--) {
            ch = *p;
            if (!ISCELEADER(v, ch))
                  newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp);
            else {
                  assert(singleton(v->cm, ch));
                  assert(leads != NULL);
                  if (!haschr(leads, ch))
                        addchr(leads, ch);
            }
      }

      /* and the ranges */
      for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--) {
            from = *p;
            to = *(p+1);
            while (from <= to && (ce = nextleader(v, from, to)) != NOCELT) {
                  if (from < ce)
                        subrange(v, from, ce - 1, lp, rp);
                  assert(singleton(v->cm, ce));
                  assert(leads != NULL);
                  if (!haschr(leads, ce))
                        addchr(leads, ce);
                  from = ce + 1;
            }
            if (from <= to)
                  subrange(v, from, to, lp, rp);
      }

      if ((leads == NULL || leads->nchrs == 0) && cv->nmcces == 0)
            return;

      /* deal with the MCCE leaders */
      NOTE(REG_ULOCALE);
      for (p = leads->chrs, i = leads->nchrs; i > 0; p++, i--) {
            co = GETCOLOR(v->cm, *p);
            a = findarc(lp, PLAIN, co);
            if (a != NULL)
                  s = a->to;
            else {
                  s = newstate(v->nfa);
                  NOERR();
                  newarc(v->nfa, PLAIN, co, lp, s);
                  NOERR();
            }
            pa = findarc(v->mccepbegin, PLAIN, co);
            assert(pa != NULL);
            ps = pa->to;
            newarc(v->nfa, '$', 1, s, rp);
            newarc(v->nfa, '$', 0, s, rp);
            colorcomplement(v->nfa, v->cm, AHEAD, ps, s, rp);
            NOERR();
      }

      /* and the MCCEs */
      for (i = 0; i < cv->nmcces; i++) {
            p = cv->mcces[i];
            assert(singleton(v->cm, *p));
            if (!singleton(v->cm, *p)) {
                  ERR(REG_ASSERT);
                  return;
            }
            ch = *p++;
            co = GETCOLOR(v->cm, ch);
            a = findarc(lp, PLAIN, co);
            if (a != NULL)
                  s = a->to;
            else {
                  s = newstate(v->nfa);
                  NOERR();
                  newarc(v->nfa, PLAIN, co, lp, s);
                  NOERR();
            }
            assert(*p != 0);  /* at least two chars */
            assert(singleton(v->cm, *p));
            ch = *p++;
            co = GETCOLOR(v->cm, ch);
            assert(*p == 0);  /* and only two, for now */
            newarc(v->nfa, PLAIN, co, s, rp);
            NOERR();
      }
}

/*
 - nextleader - find next MCCE leader within range
 ^ static celt nextleader(struct vars *, pchr, pchr);
 */
static celt             /* NOCELT means none */
nextleader(v, from, to)
struct vars *v;
pchr from;
pchr to;
{
      int i;
      chr *p;
      chr ch;
      celt it = NOCELT;

      if (v->mcces == NULL)
            return it;

      for (i = v->mcces->nchrs, p = v->mcces->chrs; i > 0; i--, p++) {
            ch = *p;
            if (from <= ch && ch <= to)
                  if (it == NOCELT || ch < it)
                        it = ch;
      }
      return it;
}

/*
 - wordchrs - set up word-chr list for word-boundary stuff, if needed
 * The list is kept as a bunch of arcs between two dummy states; it's
 * disposed of by the unreachable-states sweep in NFA optimization.
 * Does NEXT().  Must not be called from any unusual lexical context.
 * This should be reconciled with the \w etc. handling in lex.c, and
 * should be cleaned up to reduce dependencies on input scanning.
 ^ static VOID wordchrs(struct vars *);
 */
static VOID
wordchrs(v)
struct vars *v;
{
      struct state *left;
      struct state *right;

      if (v->wordchrs != NULL) {
            NEXT();           /* for consistency */
            return;
      }

      left = newstate(v->nfa);
      right = newstate(v->nfa);
      NOERR();
      /* fine point:  implemented with [::], and lexer will set REG_ULOCALE */
      lexword(v);
      NEXT();
      assert(v->savenow != NULL && SEE('['));
      bracket(v, left, right);
      assert((v->savenow != NULL && SEE(']')) || ISERR());
      NEXT();
      NOERR();
      v->wordchrs = left;
}

/*
 - subre - allocate a subre
 ^ static struct subre *subre(struct vars *, int, int, struct state *,
 ^    struct state *);
 */
static struct subre *
subre(v, op, flags, begin, end)
struct vars *v;
int op;
int flags;
struct state *begin;
struct state *end;
{
      struct subre *ret;

      ret = v->treefree;
      if (ret != NULL)
            v->treefree = ret->left;
      else {
            ret = (struct subre *)MALLOC(sizeof(struct subre));
            if (ret == NULL) {
                  ERR(REG_ESPACE);
                  return NULL;
            }
            ret->chain = v->treechain;
            v->treechain = ret;
      }

      assert(strchr("|.b(=", op) != NULL);

      ret->op = op;
      ret->flags = flags;
      ret->retry = 0;
      ret->subno = 0;
      ret->min = ret->max = 1;
      ret->left = NULL;
      ret->right = NULL;
      ret->begin = begin;
      ret->end = end;
      ZAPCNFA(ret->cnfa);

      return ret;
}

/*
 - freesubre - free a subRE subtree
 ^ static VOID freesubre(struct vars *, struct subre *);
 */
static VOID
freesubre(v, sr)
struct vars *v;               /* might be NULL */
struct subre *sr;
{
      if (sr == NULL)
            return;

      if (sr->left != NULL)
            freesubre(v, sr->left);
      if (sr->right != NULL)
            freesubre(v, sr->right);

      freesrnode(v, sr);
}

/*
 - freesrnode - free one node in a subRE subtree
 ^ static VOID freesrnode(struct vars *, struct subre *);
 */
static VOID
freesrnode(v, sr)
struct vars *v;               /* might be NULL */
struct subre *sr;
{
      if (sr == NULL)
            return;

      if (!NULLCNFA(sr->cnfa))
            freecnfa(&sr->cnfa);
      sr->flags = 0;

      if (v != NULL) {
            sr->left = v->treefree;
            v->treefree = sr;
      } else
            FREE(sr);
}

/*
 - optst - optimize a subRE subtree
 ^ static VOID optst(struct vars *, struct subre *);
 */
static VOID
optst(v, t)
struct vars *v;
struct subre *t;
{
      if (t == NULL)
            return;

      /* recurse through children */
      if (t->left != NULL)
            optst(v, t->left);
      if (t->right != NULL)
            optst(v, t->right);
}

/*
 - numst - number tree nodes (assigning retry indexes)
 ^ static int numst(struct subre *, int);
 */
static int              /* next number */
numst(t, start)
struct subre *t;
int start;              /* starting point for subtree numbers */
{
      int i;

      assert(t != NULL);

      i = start;
      t->retry = (short)i++;
      if (t->left != NULL)
            i = numst(t->left, i);
      if (t->right != NULL)
            i = numst(t->right, i);
      return i;
}

/*
 - markst - mark tree nodes as INUSE
 ^ static VOID markst(struct subre *);
 */
static VOID
markst(t)
struct subre *t;
{
      assert(t != NULL);

      t->flags |= INUSE;
      if (t->left != NULL)
            markst(t->left);
      if (t->right != NULL)
            markst(t->right);
}

/*
 - cleanst - free any tree nodes not marked INUSE
 ^ static VOID cleanst(struct vars *);
 */
static VOID
cleanst(v)
struct vars *v;
{
      struct subre *t;
      struct subre *next;

      for (t = v->treechain; t != NULL; t = next) {
            next = t->chain;
            if (!(t->flags&INUSE))
                  FREE(t);
      }
      v->treechain = NULL;
      v->treefree = NULL;           /* just on general principles */
}

/*
 - nfatree - turn a subRE subtree into a tree of compacted NFAs
 ^ static long nfatree(struct vars *, struct subre *, FILE *);
 */
static long             /* optimize results from top node */
nfatree(v, t, f)
struct vars *v;
struct subre *t;
FILE *f;                /* for debug output */
{
      assert(t != NULL && t->begin != NULL);

      if (t->left != NULL)
            (DISCARD)nfatree(v, t->left, f);
      if (t->right != NULL)
            (DISCARD)nfatree(v, t->right, f);

      return nfanode(v, t, f);
}

/*
 - nfanode - do one NFA for nfatree
 ^ static long nfanode(struct vars *, struct subre *, FILE *);
 */
static long             /* optimize results */
nfanode(v, t, f)
struct vars *v;
struct subre *t;
FILE *f;                /* for debug output */
{
      struct nfa *nfa;
      long ret = 0;
      char idbuf[50];

      assert(t->begin != NULL);

      if (f != NULL)
            fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
                                    stid(t, idbuf, sizeof(idbuf)));
      nfa = newnfa(v, v->cm, v->nfa);
      NOERRZ();
      dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
      if (!ISERR()) {
            specialcolors(nfa);
            ret = optimize(nfa, f);
      }
      if (!ISERR())
            compact(nfa, &t->cnfa);

      freenfa(nfa);
      return ret;
}

/*
 - newlacon - allocate a lookahead-constraint subRE
 ^ static int newlacon(struct vars *, struct state *, struct state *, int);
 */
static int              /* lacon number */
newlacon(v, begin, end, pos)
struct vars *v;
struct state *begin;
struct state *end;
int pos;
{
      int n;
      struct subre *sub;

      if (v->nlacons == 0) {
            v->lacons = (struct subre *)MALLOC(2 * sizeof(struct subre));
            n = 1;            /* skip 0th */
            v->nlacons = 2;
      } else {
            v->lacons = (struct subre *)REALLOC(v->lacons,
                              (v->nlacons+1)*sizeof(struct subre));
            n = v->nlacons++;
      }
      if (v->lacons == NULL) {
            ERR(REG_ESPACE);
            return 0;
      }
      sub = &v->lacons[n];
      sub->begin = begin;
      sub->end = end;
      sub->subno = pos;
      ZAPCNFA(sub->cnfa);
      return n;
}

/*
 - freelacons - free lookahead-constraint subRE vector
 ^ static VOID freelacons(struct subre *, int);
 */
static VOID
freelacons(subs, n)
struct subre *subs;
int n;
{
      struct subre *sub;
      int i;

      assert(n > 0);
      for (sub = subs + 1, i = n - 1; i > 0; sub++, i--)    /* no 0th */
            if (!NULLCNFA(sub->cnfa))
                  freecnfa(&sub->cnfa);
      FREE(subs);
}

/*
 - rfree - free a whole RE (insides of regfree)
 ^ static VOID rfree(regex_t *);
 */
static VOID
rfree(re)
regex_t *re;
{
      struct guts *g;

      if (re == NULL || re->re_magic != REMAGIC)
            return;

      re->re_magic = 0; /* invalidate RE */
      g = (struct guts *)re->re_guts;
      re->re_guts = NULL;
      re->re_fns = NULL;
      g->magic = 0;
      freecm(&g->cmap);
      if (g->tree != NULL)
            freesubre((struct vars *)NULL, g->tree);
      if (g->lacons != NULL)
            freelacons(g->lacons, g->nlacons);
      if (!NULLCNFA(g->search))
            freecnfa(&g->search);
      FREE(g);
}

/*
 - dump - dump an RE in human-readable form
 ^ static VOID dump(regex_t *, FILE *);
 */
static VOID
dump(re, f)
regex_t *re;
FILE *f;
{
#ifdef REG_DEBUG
      struct guts *g;
      int i;

      if (re->re_magic != REMAGIC)
            fprintf(f, "bad magic number (0x%x not 0x%x)\n", re->re_magic,
                                                REMAGIC);
      if (re->re_guts == NULL) {
            fprintf(f, "NULL guts!!!\n");
            return;
      }
      g = (struct guts *)re->re_guts;
      if (g->magic != GUTSMAGIC)
            fprintf(f, "bad guts magic number (0x%x not 0x%x)\n", g->magic,
                                                GUTSMAGIC);

      fprintf(f, "\n\n\n========= DUMP ==========\n");
      fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n", 
            re->re_nsub, re->re_info, re->re_csize, g->ntree);

      dumpcolors(&g->cmap, f);
      if (!NULLCNFA(g->search)) {
            printf("\nsearch:\n");
            dumpcnfa(&g->search, f);
      }
      for (i = 1; i < g->nlacons; i++) {
            fprintf(f, "\nla%d (%s):\n", i,
                        (g->lacons[i].subno) ? "positive" : "negative");
            dumpcnfa(&g->lacons[i].cnfa, f);
      }
      fprintf(f, "\n");
      dumpst(g->tree, f, 0);
#endif
}

/*
 - dumpst - dump a subRE tree
 ^ static VOID dumpst(struct subre *, FILE *, int);
 */
static VOID
dumpst(t, f, nfapresent)
struct subre *t;
FILE *f;
int nfapresent;               /* is the original NFA still around? */
{
      if (t == NULL)
            fprintf(f, "null tree\n");
      else
            stdump(t, f, nfapresent);
      fflush(f);
}

/*
 - stdump - recursive guts of dumpst
 ^ static VOID stdump(struct subre *, FILE *, int);
 */
static VOID
stdump(t, f, nfapresent)
struct subre *t;
FILE *f;
int nfapresent;               /* is the original NFA still around? */
{
      char idbuf[50];

      fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op);
      if (t->flags&LONGER)
            fprintf(f, " longest");
      if (t->flags&SHORTER)
            fprintf(f, " shortest");
      if (t->flags&MIXED)
            fprintf(f, " hasmixed");
      if (t->flags&CAP)
            fprintf(f, " hascapture");
      if (t->flags&BACKR)
            fprintf(f, " hasbackref");
      if (!(t->flags&INUSE))
            fprintf(f, " UNUSED");
      if (t->subno != 0)
            fprintf(f, " (#%d)", t->subno);
      if (t->min != 1 || t->max != 1) {
            fprintf(f, " {%d,", t->min);
            if (t->max != INFINITY)
                  fprintf(f, "%d", t->max);
            fprintf(f, "}");
      }
      if (nfapresent)
            fprintf(f, " %ld-%ld", (long)t->begin->no, (long)t->end->no);
      if (t->left != NULL)
            fprintf(f, " L:%s", stid(t->left, idbuf, sizeof(idbuf)));
      if (t->right != NULL)
            fprintf(f, " R:%s", stid(t->right, idbuf, sizeof(idbuf)));
      if (!NULLCNFA(t->cnfa)) {
            fprintf(f, "\n");
            dumpcnfa(&t->cnfa, f);
            fprintf(f, "\n");
      }
      if (t->left != NULL)
            stdump(t->left, f, nfapresent);
      if (t->right != NULL)
            stdump(t->right, f, nfapresent);
}

/*
 - stid - identify a subtree node for dumping
 ^ static char *stid(struct subre *, char *, size_t);
 */
static char *                 /* points to buf or constant string */
stid(t, buf, bufsize)
struct subre *t;
char *buf;
size_t bufsize;
{
      /* big enough for hex int or decimal t->retry? */
      if (bufsize < sizeof(void*)*2 + 3 || bufsize < sizeof(t->retry)*3 + 1)
            return "unable";
      if (t->retry != 0)
            sprintf(buf, "%d", t->retry);
      else
            sprintf(buf, "%p", t);
      return buf;
}

#include "regc_lex.c"
#include "regc_color.c"
#include "regc_nfa.c"
#include "regc_cvec.c"
#include "regc_locale.c"

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