+int flags;
+{
+ struct vars var;
+ register struct vars *v = &var;
+ int st;
+ size_t n;
+ int backref;
+# define LOCALMAT 20
+ regmatch_t mat[LOCALMAT];
+# define LOCALMEM 40
+ regoff_t mem[LOCALMEM];
+
+ /* sanity checks */
+ if (re == NULL || string == NULL || re->re_magic != REMAGIC)
+ return REG_INVARG;
+ if (re->re_csize != sizeof(chr))
+ return REG_MIXED;
+
+ /* setup */
+ v->re = re;
+ v->g = (struct guts *)re->re_guts;
+ if ((v->g->cflags®_EXPECT) && details == NULL)
+ return REG_INVARG;
+ if (v->g->info®_UIMPOSSIBLE)
+ return REG_NOMATCH;
+ backref = (v->g->info®_UBACKREF) ? 1 : 0;
+ v->eflags = flags;
+ if (v->g->cflags®_NOSUB)
+ nmatch = 0; /* override client */
+ v->nmatch = nmatch;
+ if (backref) {
+ /* need work area */
+ if (v->g->nsub + 1 <= LOCALMAT)
+ v->pmatch = mat;
+ else
+ v->pmatch = (regmatch_t *)MALLOC((v->g->nsub + 1) *
+ sizeof(regmatch_t));
+ if (v->pmatch == NULL)
+ return REG_ESPACE;
+ v->nmatch = v->g->nsub + 1;
+ } else
+ v->pmatch = pmatch;
+ v->details = details;
+ v->start = (chr *)string;
+ v->stop = (chr *)string + len;
+ v->err = 0;
+ if (backref) {
+ /* need retry memory */
+ assert(v->g->ntree >= 0);
+ n = (size_t)v->g->ntree;
+ if (n <= LOCALMEM)
+ v->mem = mem;
+ else
+ v->mem = (regoff_t *)MALLOC(n*sizeof(regoff_t));
+ if (v->mem == NULL) {
+ if (v->pmatch != pmatch && v->pmatch != mat)
+ FREE(v->pmatch);
+ return REG_ESPACE;
+ }
+ } else
+ v->mem = NULL;
+
+ /* do it */
+ assert(v->g->tree != NULL);
+ if (backref)
+ st = cfind(v, &v->g->tree->cnfa, &v->g->cmap);
+ else
+ st = find(v, &v->g->tree->cnfa, &v->g->cmap);
+
+ /* copy (portion of) match vector over if necessary */
+ if (st == REG_OKAY && v->pmatch != pmatch && nmatch > 0) {
+ zapsubs(pmatch, nmatch);
+ n = (nmatch < v->nmatch) ? nmatch : v->nmatch;
+ memcpy(VS(pmatch), VS(v->pmatch), n*sizeof(regmatch_t));
+ }
+
+ /* clean up */
+ if (v->pmatch != pmatch && v->pmatch != mat)
+ FREE(v->pmatch);
+ if (v->mem != NULL && v->mem != mem)
+ FREE(v->mem);
+ return st;
+}
+
+/*
+ - find - find a match for the main NFA (no-complications case)
+ ^ static int find(struct vars *, struct cnfa *, struct colormap *);
+ */
+static int
+find(v, cnfa, cm)
+struct vars *v;
+struct cnfa *cnfa;
+struct colormap *cm;
+{
+ struct dfa *s;
+ struct dfa *d;
+ chr *begin;
+ chr *end = NULL;
+ chr *cold;
+ chr *open; /* open and close of range of possible starts */
+ chr *close;
+ int hitend;
+ int shorter = (v->g->tree->flags&SHORTER) ? 1 : 0;
+
+ /* first, a shot with the search RE */
+ s = newdfa(v, &v->g->search, cm, &v->dfa1);
+ assert(!(ISERR() && s != NULL));
+ NOERR();
+ MDEBUG(("\nsearch at %ld\n", LOFF(v->start)));
+ cold = NULL;
+ close = shortest(v, s, v->start, v->start, v->stop, &cold, (int *)NULL);
+ freedfa(s);
+ NOERR();
+ if (v->g->cflags®_EXPECT) {
+ assert(v->details != NULL);
+ if (cold != NULL)
+ v->details->rm_extend.rm_so = OFF(cold);
+ else
+ v->details->rm_extend.rm_so = OFF(v->stop);
+ v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */
+ }
+ if (close == NULL) /* not found */
+ return REG_NOMATCH;
+ if (v->nmatch == 0) /* found, don't need exact location */
+ return REG_OKAY;
+
+ /* find starting point and match */
+ assert(cold != NULL);
+ open = cold;
+ cold = NULL;
+ MDEBUG(("between %ld and %ld\n", LOFF(open), LOFF(close)));
+ d = newdfa(v, cnfa, cm, &v->dfa1);
+ assert(!(ISERR() && d != NULL));
+ NOERR();
+ for (begin = open; begin <= close; begin++) {
+ MDEBUG(("\nfind trying at %ld\n", LOFF(begin)));
+ if (shorter)
+ end = shortest(v, d, begin, begin, v->stop,
+ (chr **)NULL, &hitend);
+ else
+ end = longest(v, d, begin, v->stop, &hitend);
+ NOERR();
+ if (hitend && cold == NULL)
+ cold = begin;
+ if (end != NULL)
+ break; /* NOTE BREAK OUT */
+ }
+ assert(end != NULL); /* search RE succeeded so loop should */
+ freedfa(d);
+
+ /* and pin down details */
+ assert(v->nmatch > 0);
+ v->pmatch[0].rm_so = OFF(begin);
+ v->pmatch[0].rm_eo = OFF(end);
+ if (v->g->cflags®_EXPECT) {
+ if (cold != NULL)
+ v->details->rm_extend.rm_so = OFF(cold);
+ else
+ v->details->rm_extend.rm_so = OFF(v->stop);
+ v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */
+ }
+ if (v->nmatch == 1) /* no need for submatches */
+ return REG_OKAY;
+
+ /* submatches */
+ zapsubs(v->pmatch, v->nmatch);
+ return dissect(v, v->g->tree, begin, end);
+}
+
+/*
+ - cfind - find a match for the main NFA (with complications)
+ ^ static int cfind(struct vars *, struct cnfa *, struct colormap *);
+ */
+static int
+cfind(v, cnfa, cm)
+struct vars *v;
+struct cnfa *cnfa;
+struct colormap *cm;
+{
+ struct dfa *s;
+ struct dfa *d;
+ chr *cold;
+ int ret;
+
+ s = newdfa(v, &v->g->search, cm, &v->dfa1);
+ NOERR();
+ d = newdfa(v, cnfa, cm, &v->dfa2);
+ if (ISERR()) {
+ assert(d == NULL);
+ freedfa(s);
+ return v->err;
+ }
+ cold = NULL;// WX: fix gcc warnings about cold being possibly uninitialized
+ ret = cfindloop(v, cnfa, cm, d, s, &cold);
+
+ freedfa(d);
+ freedfa(s);
+ NOERR();
+ if (v->g->cflags®_EXPECT) {
+ assert(v->details != NULL);
+ if (cold != NULL)
+ v->details->rm_extend.rm_so = OFF(cold);
+ else
+ v->details->rm_extend.rm_so = OFF(v->stop);
+ v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */
+ }
+ return ret;
+}
+
+/*
+ - cfindloop - the heart of cfind
+ ^ static int cfindloop(struct vars *, struct cnfa *, struct colormap *,
+ ^ struct dfa *, struct dfa *, chr **);
+ */
+static int
+cfindloop(v, cnfa, cm, d, s, coldp)
+struct vars *v;
+struct cnfa *cnfa;
+struct colormap *cm;
+struct dfa *d;
+struct dfa *s;
+chr **coldp; /* where to put coldstart pointer */
+{
+ chr *begin;
+ chr *end;
+ chr *cold;
+ chr *open; /* open and close of range of possible starts */
+ chr *close;
+ chr *estart;
+ chr *estop;
+ int er;
+ int shorter = v->g->tree->flags&SHORTER;
+ int hitend;
+
+ assert(d != NULL && s != NULL);
+ cold = NULL;
+ close = v->start;
+ do {
+ MDEBUG(("\ncsearch at %ld\n", LOFF(close)));
+ close = shortest(v, s, close, close, v->stop, &cold, (int *)NULL);
+ if (close == NULL)
+ break; /* NOTE BREAK */
+ assert(cold != NULL);
+ open = cold;
+ cold = NULL;
+ MDEBUG(("cbetween %ld and %ld\n", LOFF(open), LOFF(close)));
+ for (begin = open; begin <= close; begin++) {
+ MDEBUG(("\ncfind trying at %ld\n", LOFF(begin)));
+ estart = begin;
+ estop = v->stop;
+ for (;;) {
+ if (shorter)
+ end = shortest(v, d, begin, estart,
+ estop, (chr **)NULL, &hitend);
+ else
+ end = longest(v, d, begin, estop,
+ &hitend);
+ if (hitend && cold == NULL)
+ cold = begin;
+ if (end == NULL)
+ break; /* NOTE BREAK OUT */
+ MDEBUG(("tentative end %ld\n", LOFF(end)));
+ zapsubs(v->pmatch, v->nmatch);
+ zapmem(v, v->g->tree);
+ er = cdissect(v, v->g->tree, begin, end);
+ if (er == REG_OKAY) {
+ if (v->nmatch > 0) {
+ v->pmatch[0].rm_so = OFF(begin);
+ v->pmatch[0].rm_eo = OFF(end);
+ }
+ *coldp = cold;
+ return REG_OKAY;
+ }
+ if (er != REG_NOMATCH) {
+ ERR(er);
+ return er;
+ }
+ if ((shorter) ? end == estop : end == begin) {
+ /* no point in trying again */
+ *coldp = cold;
+ return REG_NOMATCH;
+ }
+ /* go around and try again */
+ if (shorter)
+ estart = end + 1;
+ else
+ estop = end - 1;
+ }
+ }
+ } while (close < v->stop);
+
+ *coldp = cold;
+ return REG_NOMATCH;
+}
+
+/*
+ - zapsubs - initialize the subexpression matches to "no match"
+ ^ static VOID zapsubs(regmatch_t *, size_t);
+ */
+static VOID
+zapsubs(p, n)
+regmatch_t *p;
+size_t n;
+{
+ size_t i;
+
+ for (i = n-1; i > 0; i--) {
+ p[i].rm_so = -1;
+ p[i].rm_eo = -1;
+ }
+}
+
+/*
+ - zapmem - initialize the retry memory of a subtree to zeros
+ ^ static VOID zapmem(struct vars *, struct subre *);
+ */
+static VOID
+zapmem(v, t)
+struct vars *v;
+struct subre *t;
+{
+ if (t == NULL)
+ return;
+
+ assert(v->mem != NULL);
+ v->mem[t->retry] = 0;
+ if (t->op == '(') {
+ assert(t->subno > 0);
+ v->pmatch[t->subno].rm_so = -1;
+ v->pmatch[t->subno].rm_eo = -1;
+ }
+
+ if (t->left != NULL)
+ zapmem(v, t->left);
+ if (t->right != NULL)
+ zapmem(v, t->right);
+}
+
+/*
+ - subset - set any subexpression relevant to a successful subre
+ ^ static VOID subset(struct vars *, struct subre *, chr *, chr *);
+ */
+static VOID
+subset(v, sub, begin, end)
+struct vars *v;
+struct subre *sub;
+chr *begin;
+chr *end;
+{
+ int n = sub->subno;
+
+ assert(n > 0);
+ if ((size_t)n >= v->nmatch)
+ return;
+
+ MDEBUG(("setting %d\n", n));
+ v->pmatch[n].rm_so = OFF(begin);
+ v->pmatch[n].rm_eo = OFF(end);
+}
+
+/*
+ - dissect - determine subexpression matches (uncomplicated case)
+ ^ static int dissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+dissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ assert(t != NULL);
+ MDEBUG(("dissect %ld-%ld\n", LOFF(begin), LOFF(end)));
+
+ switch (t->op) {
+ case '=': /* terminal node */
+ assert(t->left == NULL && t->right == NULL);
+ return REG_OKAY; /* no action, parent did the work */
+ break;
+ case '|': /* alternation */
+ assert(t->left != NULL);
+ return altdissect(v, t, begin, end);
+ break;
+ case 'b': /* back ref -- shouldn't be calling us! */
+ return REG_ASSERT;
+ break;
+ case '.': /* concatenation */
+ assert(t->left != NULL && t->right != NULL);
+ return condissect(v, t, begin, end);
+ break;
+ case '(': /* capturing */
+ assert(t->left != NULL && t->right == NULL);
+ assert(t->subno > 0);
+ subset(v, t, begin, end);
+ return dissect(v, t->left, begin, end);
+ break;
+ default:
+ return REG_ASSERT;
+ break;
+ }
+}
+
+/*
+ - condissect - determine concatenation subexpression matches (uncomplicated)
+ ^ static int condissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+condissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */