--- projs/trunk/shared_source/c_tcl_base_7_5_w_mods/rege_dfa.c	2016/10/30 04:21:11	64
+++ projs/trunk/shared_source/c_tcl_base_7_5_w_mods/rege_dfa.c	2016/11/05 11:07:06	71
@@ -1,689 +1,680 @@
-/* $Header$ */
-
-/*
- * DFA routines
- * This file is #included by regexec.c.
- *
- * 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.
- *
- */
-
-/*
- - longest - longest-preferred matching engine
- ^ static chr *longest(struct vars *, struct dfa *, chr *, chr *, int *);
- */
-static chr *			/* endpoint, or NULL */
-longest(v, d, start, stop, hitstopp)
-struct vars *v;			/* used only for debug and exec flags */
-struct dfa *d;
-chr *start;			/* where the match should start */
-chr *stop;			/* match must end at or before here */
-int *hitstopp;			/* record whether hit v->stop, if non-NULL */
-{
-	chr *cp;
-	chr *realstop = (stop == v->stop) ? stop : stop + 1;
-	color co;
-	struct sset *css;
-	struct sset *ss;
-	chr *post;
-	int i;
-	struct colormap *cm = d->cm;
-
-	/* initialize */
-	css = initialize(v, d, start);
-	cp = start;
-	if (hitstopp != NULL)
-		*hitstopp = 0;
-
-	/* startup */
-	FDEBUG(("+++ startup +++\n"));
-	if (cp == v->start) {
-		co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
-		FDEBUG(("color %ld\n", (long)co));
-	} else {
-		co = GETCOLOR(cm, *(cp - 1));
-		FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
-	}
-	css = miss(v, d, css, co, cp, start);
-	if (css == NULL)
-		return NULL;
-	css->lastseen = cp;
-
-	/* main loop */
-	if (v->eflags&REG_FTRACE)
-		while (cp < realstop) {
-			FDEBUG(("+++ at c%d +++\n", css - d->ssets));
-			co = GETCOLOR(cm, *cp);
-			FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
-			ss = css->outs[co];
-			if (ss == NULL) {
-				ss = miss(v, d, css, co, cp+1, start);
-				if (ss == NULL)
-					break;	/* NOTE BREAK OUT */
-			}
-			cp++;
-			ss->lastseen = cp;
-			css = ss;
-		}
-	else
-		while (cp < realstop) {
-			co = GETCOLOR(cm, *cp);
-			ss = css->outs[co];
-			if (ss == NULL) {
-				ss = miss(v, d, css, co, cp+1, start);
-				if (ss == NULL)
-					break;	/* NOTE BREAK OUT */
-			}
-			cp++;
-			ss->lastseen = cp;
-			css = ss;
-		}
-
-	/* shutdown */
-	FDEBUG(("+++ shutdown at c%d +++\n", css - d->ssets));
-	if (cp == v->stop && stop == v->stop) {
-		if (hitstopp != NULL)
-			*hitstopp = 1;
-		co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
-		FDEBUG(("color %ld\n", (long)co));
-		ss = miss(v, d, css, co, cp, start);
-		/* special case:  match ended at eol? */
-		if (ss != NULL && (ss->flags&POSTSTATE))
-			return cp;
-		else if (ss != NULL)
-			ss->lastseen = cp;	/* to be tidy */
-	}
-
-	/* find last match, if any */
-	post = d->lastpost;
-	for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
-		if ((ss->flags&POSTSTATE) && post != ss->lastseen &&
-					(post == NULL || post < ss->lastseen))
-			post = ss->lastseen;
-	if (post != NULL)		/* found one */
-		return post - 1;
-
-	return NULL;
-}
-
-/*
- - shortest - shortest-preferred matching engine
- ^ static chr *shortest(struct vars *, struct dfa *, chr *, chr *, chr *,
- ^ 	chr **, int *);
- */
-static chr *			/* endpoint, or NULL */
-shortest(v, d, start, min, max, coldp, hitstopp)
-struct vars *v;
-struct dfa *d;
-chr *start;			/* where the match should start */
-chr *min;			/* match must end at or after here */
-chr *max;			/* match must end at or before here */
-chr **coldp;			/* store coldstart pointer here, if nonNULL */
-int *hitstopp;			/* record whether hit v->stop, if non-NULL */
-{
-	chr *cp;
-	chr *realmin = (min == v->stop) ? min : min + 1;
-	chr *realmax = (max == v->stop) ? max : max + 1;
-	color co;
-	struct sset *css;
-	struct sset *ss;
-	struct colormap *cm = d->cm;
-
-	/* initialize */
-	css = initialize(v, d, start);
-	cp = start;
-	if (hitstopp != NULL)
-		*hitstopp = 0;
-
-	/* startup */
-	FDEBUG(("--- startup ---\n"));
-	if (cp == v->start) {
-		co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
-		FDEBUG(("color %ld\n", (long)co));
-	} else {
-		co = GETCOLOR(cm, *(cp - 1));
-		FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
-	}
-	css = miss(v, d, css, co, cp, start);
-	if (css == NULL)
-		return NULL;
-	css->lastseen = cp;
-	ss = css;
-
-	/* main loop */
-	if (v->eflags&REG_FTRACE)
-		while (cp < realmax) {
-			FDEBUG(("--- at c%d ---\n", css - d->ssets));
-			co = GETCOLOR(cm, *cp);
-			FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
-			ss = css->outs[co];
-			if (ss == NULL) {
-				ss = miss(v, d, css, co, cp+1, start);
-				if (ss == NULL)
-					break;	/* NOTE BREAK OUT */
-			}
-			cp++;
-			ss->lastseen = cp;
-			css = ss;
-			if ((ss->flags&POSTSTATE) && cp >= realmin)
-				break;		/* NOTE BREAK OUT */
-		}
-	else
-		while (cp < realmax) {
-			co = GETCOLOR(cm, *cp);
-			ss = css->outs[co];
-			if (ss == NULL) {
-				ss = miss(v, d, css, co, cp+1, start);
-				if (ss == NULL)
-					break;	/* NOTE BREAK OUT */
-			}
-			cp++;
-			ss->lastseen = cp;
-			css = ss;
-			if ((ss->flags&POSTSTATE) && cp >= realmin)
-				break;		/* NOTE BREAK OUT */
-		}
-
-	if (ss == NULL)
-		return NULL;
-
-	if (coldp != NULL)	/* report last no-progress state set, if any */
-		*coldp = lastcold(v, d);
-
-	if ((ss->flags&POSTSTATE) && cp > min) {
-		assert(cp >= realmin);
-		cp--;
-	} else if (cp == v->stop && max == v->stop) {
-		co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
-		FDEBUG(("color %ld\n", (long)co));
-		ss = miss(v, d, css, co, cp, start);
-		/* match might have ended at eol */
-		if ((ss == NULL || !(ss->flags&POSTSTATE)) && hitstopp != NULL)
-			*hitstopp = 1;
-	}
-
-	if (ss == NULL || !(ss->flags&POSTSTATE))
-		return NULL;
-
-	return cp;
-}
-
-/*
- - lastcold - determine last point at which no progress had been made
- ^ static chr *lastcold(struct vars *, struct dfa *);
- */
-static chr *			/* endpoint, or NULL */
-lastcold(v, d)
-struct vars *v;
-struct dfa *d;
-{
-	struct sset *ss;
-	chr *nopr;
-	int i;
-
-	nopr = d->lastnopr;
-	if (nopr == NULL)
-		nopr = v->start;
-	for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
-		if ((ss->flags&NOPROGRESS) && nopr < ss->lastseen)
-			nopr = ss->lastseen;
-	return nopr;
-}
-
-/*
- - newdfa - set up a fresh DFA
- ^ static struct dfa *newdfa(struct vars *, struct cnfa *,
- ^ 	struct colormap *, struct smalldfa *);
- */
-static struct dfa *
-newdfa(v, cnfa, cm, small)
-struct vars *v;
-struct cnfa *cnfa;
-struct colormap *cm;
-struct smalldfa *small;		/* preallocated space, may be NULL */
-{
-	struct dfa *d;
-	size_t nss = cnfa->nstates * 2;
-	int wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
-	struct smalldfa *smallwas = small;
-
-	assert(cnfa != NULL && cnfa->nstates != 0);
-
-	if (nss <= FEWSTATES && cnfa->ncolors <= FEWCOLORS) {
-		assert(wordsper == 1);
-		if (small == NULL) {
-			small = (struct smalldfa *)MALLOC(
-						sizeof(struct smalldfa));
-			if (small == NULL) {
-				ERR(REG_ESPACE);
-				return NULL;
-			}
-		}
-		d = &small->dfa;
-		d->ssets = small->ssets;
-		d->statesarea = small->statesarea;
-		d->work = &d->statesarea[nss];
-		d->outsarea = small->outsarea;
-		d->incarea = small->incarea;
-		d->cptsmalloced = 0;
-		d->mallocarea = (smallwas == NULL) ? (char *)small : NULL;
-	} else {
-		d = (struct dfa *)MALLOC(sizeof(struct dfa));
-		if (d == NULL) {
-			ERR(REG_ESPACE);
-			return NULL;
-		}
-		d->ssets = (struct sset *)MALLOC(nss * sizeof(struct sset));
-		d->statesarea = (unsigned *)MALLOC((nss+WORK) * wordsper *
-							sizeof(unsigned));
-		d->work = &d->statesarea[nss * wordsper];
-		d->outsarea = (struct sset **)MALLOC(nss * cnfa->ncolors *
-							sizeof(struct sset *));
-		d->incarea = (struct arcp *)MALLOC(nss * cnfa->ncolors *
-							sizeof(struct arcp));
-		d->cptsmalloced = 1;
-		d->mallocarea = (char *)d;
-		if (d->ssets == NULL || d->statesarea == NULL ||
-				d->outsarea == NULL || d->incarea == NULL) {
-			freedfa(d);
-			ERR(REG_ESPACE);
-			return NULL;
-		}
-	}
-
-	d->nssets = (v->eflags&REG_SMALL) ? 7 : nss;
-	d->nssused = 0;
-	d->nstates = cnfa->nstates;
-	d->ncolors = cnfa->ncolors;
-	d->wordsper = wordsper;
-	d->cnfa = cnfa;
-	d->cm = cm;
-	d->lastpost = NULL;
-	d->lastnopr = NULL;
-	d->search = d->ssets;
-
-	/* initialization of sset fields is done as needed */
-
-	return d;
-}
-
-/*
- - freedfa - free a DFA
- ^ static VOID freedfa(struct dfa *);
- */
-static VOID
-freedfa(d)
-struct dfa *d;
-{
-	if (d->cptsmalloced) {
-		if (d->ssets != NULL)
-			FREE(d->ssets);
-		if (d->statesarea != NULL)
-			FREE(d->statesarea);
-		if (d->outsarea != NULL)
-			FREE(d->outsarea);
-		if (d->incarea != NULL)
-			FREE(d->incarea);
-	}
-
-	if (d->mallocarea != NULL)
-		FREE(d->mallocarea);
-}
-
-/*
- - hash - construct a hash code for a bitvector
- * There are probably better ways, but they're more expensive.
- ^ static unsigned hash(unsigned *, int);
- */
-static unsigned
-hash(uv, n)
-unsigned *uv;
-int n;
-{
-	int i;
-	unsigned h;
-
-	h = 0;
-	for (i = 0; i < n; i++)
-		h ^= uv[i];
-	return h;
-}
-
-/*
- - initialize - hand-craft a cache entry for startup, otherwise get ready
- ^ static struct sset *initialize(struct vars *, struct dfa *, chr *);
- */
-static struct sset *
-initialize(v, d, start)
-struct vars *v;			/* used only for debug flags */
-struct dfa *d;
-chr *start;
-{
-	struct sset *ss;
-	int i;
-
-	/* is previous one still there? */
-	if (d->nssused > 0 && (d->ssets[0].flags&STARTER))
-		ss = &d->ssets[0];
-	else {				/* no, must (re)build it */
-		ss = getvacant(v, d, start, start);
-		for (i = 0; i < d->wordsper; i++)
-			ss->states[i] = 0;
-		BSET(ss->states, d->cnfa->pre);
-		ss->hash = HASH(ss->states, d->wordsper);
-		assert(d->cnfa->pre != d->cnfa->post);
-		ss->flags = STARTER|LOCKED|NOPROGRESS;
-		/* lastseen dealt with below */
-	}
-
-	for (i = 0; i < d->nssused; i++)
-		d->ssets[i].lastseen = NULL;
-	ss->lastseen = start;		/* maybe untrue, but harmless */
-	d->lastpost = NULL;
-	d->lastnopr = NULL;
-	return ss;
-}
-
-/*
- - miss - handle a cache miss
- ^ static struct sset *miss(struct vars *, struct dfa *, struct sset *,
- ^ 	pcolor, chr *, chr *);
- */
-static struct sset *		/* NULL if goes to empty set */
-miss(v, d, css, co, cp, start)
-struct vars *v;			/* used only for debug flags */
-struct dfa *d;
-struct sset *css;
-pcolor co;
-chr *cp;			/* next chr */
-chr *start;			/* where the attempt got started */
-{
-	struct cnfa *cnfa = d->cnfa;
-	int i;
-	unsigned h;
-	struct carc *ca;
-	struct sset *p;
-	int ispost;
-	int noprogress;
-	int gotstate;
-	int dolacons;
-	int sawlacons;
-
-	/* for convenience, we can be called even if it might not be a miss */
-	if (css->outs[co] != NULL) {
-		FDEBUG(("hit\n"));
-		return css->outs[co];
-	}
-	FDEBUG(("miss\n"));
-
-	/* first, what set of states would we end up in? */
-	for (i = 0; i < d->wordsper; i++)
-		d->work[i] = 0;
-	ispost = 0;
-	noprogress = 1;
-	gotstate = 0;
-	for (i = 0; i < d->nstates; i++)
-		if (ISBSET(css->states, i))
-			for (ca = cnfa->states[i]+1; ca->co != COLORLESS; ca++)
-				if (ca->co == co) {
-					BSET(d->work, ca->to);
-					gotstate = 1;
-					if (ca->to == cnfa->post)
-						ispost = 1;
-					if (!cnfa->states[ca->to]->co)
-						noprogress = 0;
-					FDEBUG(("%d -> %d\n", i, ca->to));
-				}
-	dolacons = (gotstate) ? (cnfa->flags&HASLACONS) : 0;
-	sawlacons = 0;
-	while (dolacons) {		/* transitive closure */
-		dolacons = 0;
-		for (i = 0; i < d->nstates; i++)
-			if (ISBSET(d->work, i))
-				for (ca = cnfa->states[i]+1; ca->co != COLORLESS;
-									ca++) {
-					if (ca->co <= cnfa->ncolors)
-						continue; /* NOTE CONTINUE */
-					sawlacons = 1;
-					if (ISBSET(d->work, ca->to))
-						continue; /* NOTE CONTINUE */
-					if (!lacon(v, cnfa, cp, ca->co))
-						continue; /* NOTE CONTINUE */
-					BSET(d->work, ca->to);
-					dolacons = 1;
-					if (ca->to == cnfa->post)
-						ispost = 1;
-					if (!cnfa->states[ca->to]->co)
-						noprogress = 0;
-					FDEBUG(("%d :> %d\n", i, ca->to));
-				}
-	}
-	if (!gotstate)
-		return NULL;
-	h = HASH(d->work, d->wordsper);
-
-	/* next, is that in the cache? */
-	for (p = d->ssets, i = d->nssused; i > 0; p++, i--)
-		if (HIT(h, d->work, p, d->wordsper)) {
-			FDEBUG(("cached c%d\n", p - d->ssets));
-			break;			/* NOTE BREAK OUT */
-		}
-	if (i == 0) {		/* nope, need a new cache entry */
-		p = getvacant(v, d, cp, start);
-		assert(p != css);
-		for (i = 0; i < d->wordsper; i++)
-			p->states[i] = d->work[i];
-		p->hash = h;
-		p->flags = (ispost) ? POSTSTATE : 0;
-		if (noprogress)
-			p->flags |= NOPROGRESS;
-		/* lastseen to be dealt with by caller */
-	}
-
-	if (!sawlacons) {		/* lookahead conds. always cache miss */
-		FDEBUG(("c%d[%d]->c%d\n", css - d->ssets, co, p - d->ssets));
-		css->outs[co] = p;
-		css->inchain[co] = p->ins;
-		p->ins.ss = css;
-		p->ins.co = (color)co;
-	}
-	return p;
-}
-
-/*
- - lacon - lookahead-constraint checker for miss()
- ^ static int lacon(struct vars *, struct cnfa *, chr *, pcolor);
- */
-static int			/* predicate:  constraint satisfied? */
-lacon(v, pcnfa, cp, co)
-struct vars *v;
-struct cnfa *pcnfa;		/* parent cnfa */
-chr *cp;
-pcolor co;			/* "color" of the lookahead constraint */
-{
-	int n;
-	struct subre *sub;
-	struct dfa *d;
-	struct smalldfa sd;
-	chr *end;
-
-	n = co - pcnfa->ncolors;
-	assert(n < v->g->nlacons && v->g->lacons != NULL);
-	FDEBUG(("=== testing lacon %d\n", n));
-	sub = &v->g->lacons[n];
-	d = newdfa(v, &sub->cnfa, &v->g->cmap, &sd);
-	if (d == NULL) {
-		ERR(REG_ESPACE);
-		return 0;
-	}
-	end = longest(v, d, cp, v->stop, (int *)NULL);
-	freedfa(d);
-	FDEBUG(("=== lacon %d match %d\n", n, (end != NULL)));
-	return (sub->subno) ? (end != NULL) : (end == NULL);
-}
-
-/*
- - getvacant - get a vacant state set
- * This routine clears out the inarcs and outarcs, but does not otherwise
- * clear the innards of the state set -- that's up to the caller.
- ^ static struct sset *getvacant(struct vars *, struct dfa *, chr *, chr *);
- */
-static struct sset *
-getvacant(v, d, cp, start)
-struct vars *v;			/* used only for debug flags */
-struct dfa *d;
-chr *cp;
-chr *start;
-{
-	int i;
-	struct sset *ss;
-	struct sset *p;
-	struct arcp ap;
-	struct arcp lastap;
-	color co;
-
-	ss = pickss(v, d, cp, start);
-	assert(!(ss->flags&LOCKED));
-
-	/* clear out its inarcs, including self-referential ones */
-	ap = ss->ins;
-	while ((p = ap.ss) != NULL) {
-		co = ap.co;
-		FDEBUG(("zapping c%d's %ld outarc\n", p - d->ssets, (long)co));
-		p->outs[co] = NULL;
-		ap = p->inchain[co];
-		p->inchain[co].ss = NULL;	/* paranoia */
-	}
-	ss->ins.ss = NULL;
-
-	/* take it off the inarc chains of the ssets reached by its outarcs */
-	for (i = 0; i < d->ncolors; i++) {
-		p = ss->outs[i];
-		assert(p != ss);		/* not self-referential */
-		if (p == NULL)
-			continue;		/* NOTE CONTINUE */
-		FDEBUG(("del outarc %d from c%d's in chn\n", i, p - d->ssets));
-		if (p->ins.ss == ss && p->ins.co == i)
-			p->ins = ss->inchain[i];
-		else {
-			assert(p->ins.ss != NULL);
-			for (ap = p->ins; ap.ss != NULL &&
-						!(ap.ss == ss && ap.co == i);
-						ap = ap.ss->inchain[ap.co])
-				lastap = ap;
-			assert(ap.ss != NULL);
-			lastap.ss->inchain[lastap.co] = ss->inchain[i];
-		}
-		ss->outs[i] = NULL;
-		ss->inchain[i].ss = NULL;
-	}
-
-	/* if ss was a success state, may need to remember location */
-	if ((ss->flags&POSTSTATE) && ss->lastseen != d->lastpost &&
-			(d->lastpost == NULL || d->lastpost < ss->lastseen))
-		d->lastpost = ss->lastseen;
-
-	/* likewise for a no-progress state */
-	if ((ss->flags&NOPROGRESS) && ss->lastseen != d->lastnopr &&
-			(d->lastnopr == NULL || d->lastnopr < ss->lastseen))
-		d->lastnopr = ss->lastseen;
-
-	return ss;
-}
-
-/*
- - pickss - pick the next stateset to be used
- ^ static struct sset *pickss(struct vars *, struct dfa *, chr *, chr *);
- */
-static struct sset *
-pickss(v, d, cp, start)
-struct vars *v;			/* used only for debug flags */
-struct dfa *d;
-chr *cp;
-chr *start;
-{
-	int i;
-	struct sset *ss;
-	struct sset *end;
-	chr *ancient;
-
-	/* shortcut for cases where cache isn't full */
-	if (d->nssused < d->nssets) {
-		i = d->nssused;
-		d->nssused++;
-		ss = &d->ssets[i];
-		FDEBUG(("new c%d\n", i));
-		/* set up innards */
-		ss->states = &d->statesarea[i * d->wordsper];
-		ss->flags = 0;
-		ss->ins.ss = NULL;
-		ss->ins.co = WHITE;		/* give it some value */
-		ss->outs = &d->outsarea[i * d->ncolors];
-		ss->inchain = &d->incarea[i * d->ncolors];
-		for (i = 0; i < d->ncolors; i++) {
-			ss->outs[i] = NULL;
-			ss->inchain[i].ss = NULL;
-		}
-		return ss;
-	}
-
-	/* look for oldest, or old enough anyway */
-	if (cp - start > d->nssets*2/3)		/* oldest 33% are expendable */
-		ancient = cp - d->nssets*2/3;
-	else
-		ancient = start;
-	for (ss = d->search, end = &d->ssets[d->nssets]; ss < end; ss++)
-		if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
-							!(ss->flags&LOCKED)) {
-			d->search = ss + 1;
-			FDEBUG(("replacing c%d\n", ss - d->ssets));
-			return ss;
-		}
-	for (ss = d->ssets, end = d->search; ss < end; ss++)
-		if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
-							!(ss->flags&LOCKED)) {
-			d->search = ss + 1;
-			FDEBUG(("replacing c%d\n", ss - d->ssets));
-			return ss;
-		}
-
-	/* nobody's old enough?!? -- something's really wrong */
-	FDEBUG(("can't find victim to replace!\n"));
-	assert(NOTREACHED);
-	ERR(REG_ASSERT);
-	return d->ssets;
-}
-
-/* $History: rege_dfa.c $
- * 
- * *****************  Version 1  *****************
- * User: Dtashley     Date: 1/02/01    Time: 12:10a
- * Created in $/IjuScripter, IjuConsole/Source/Tcl Base
- * Initial check-in.
- */ 
-
-/* End of REGE_DFA.C */
\ No newline at end of file
+/* $Header$ */
+/*
+ * DFA routines
+ * This file is #included by regexec.c.
+ *
+ * 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.
+ *
+ */
+
+/*
+ - longest - longest-preferred matching engine
+ ^ static chr *longest(struct vars *, struct dfa *, chr *, chr *, int *);
+ */
+static chr *			/* endpoint, or NULL */
+longest(v, d, start, stop, hitstopp)
+struct vars *v;			/* used only for debug and exec flags */
+struct dfa *d;
+chr *start;			/* where the match should start */
+chr *stop;			/* match must end at or before here */
+int *hitstopp;			/* record whether hit v->stop, if non-NULL */
+{
+	chr *cp;
+	chr *realstop = (stop == v->stop) ? stop : stop + 1;
+	color co;
+	struct sset *css;
+	struct sset *ss;
+	chr *post;
+	int i;
+	struct colormap *cm = d->cm;
+
+	/* initialize */
+	css = initialize(v, d, start);
+	cp = start;
+	if (hitstopp != NULL)
+		*hitstopp = 0;
+
+	/* startup */
+	FDEBUG(("+++ startup +++\n"));
+	if (cp == v->start) {
+		co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
+		FDEBUG(("color %ld\n", (long)co));
+	} else {
+		co = GETCOLOR(cm, *(cp - 1));
+		FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
+	}
+	css = miss(v, d, css, co, cp, start);
+	if (css == NULL)
+		return NULL;
+	css->lastseen = cp;
+
+	/* main loop */
+	if (v->eflags&REG_FTRACE)
+		while (cp < realstop) {
+			FDEBUG(("+++ at c%d +++\n", css - d->ssets));
+			co = GETCOLOR(cm, *cp);
+			FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
+			ss = css->outs[co];
+			if (ss == NULL) {
+				ss = miss(v, d, css, co, cp+1, start);
+				if (ss == NULL)
+					break;	/* NOTE BREAK OUT */
+			}
+			cp++;
+			ss->lastseen = cp;
+			css = ss;
+		}
+	else
+		while (cp < realstop) {
+			co = GETCOLOR(cm, *cp);
+			ss = css->outs[co];
+			if (ss == NULL) {
+				ss = miss(v, d, css, co, cp+1, start);
+				if (ss == NULL)
+					break;	/* NOTE BREAK OUT */
+			}
+			cp++;
+			ss->lastseen = cp;
+			css = ss;
+		}
+
+	/* shutdown */
+	FDEBUG(("+++ shutdown at c%d +++\n", css - d->ssets));
+	if (cp == v->stop && stop == v->stop) {
+		if (hitstopp != NULL)
+			*hitstopp = 1;
+		co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
+		FDEBUG(("color %ld\n", (long)co));
+		ss = miss(v, d, css, co, cp, start);
+		/* special case:  match ended at eol? */
+		if (ss != NULL && (ss->flags&POSTSTATE))
+			return cp;
+		else if (ss != NULL)
+			ss->lastseen = cp;	/* to be tidy */
+	}
+
+	/* find last match, if any */
+	post = d->lastpost;
+	for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
+		if ((ss->flags&POSTSTATE) && post != ss->lastseen &&
+					(post == NULL || post < ss->lastseen))
+			post = ss->lastseen;
+	if (post != NULL)		/* found one */
+		return post - 1;
+
+	return NULL;
+}
+
+/*
+ - shortest - shortest-preferred matching engine
+ ^ static chr *shortest(struct vars *, struct dfa *, chr *, chr *, chr *,
+ ^ 	chr **, int *);
+ */
+static chr *			/* endpoint, or NULL */
+shortest(v, d, start, min, max, coldp, hitstopp)
+struct vars *v;
+struct dfa *d;
+chr *start;			/* where the match should start */
+chr *min;			/* match must end at or after here */
+chr *max;			/* match must end at or before here */
+chr **coldp;			/* store coldstart pointer here, if nonNULL */
+int *hitstopp;			/* record whether hit v->stop, if non-NULL */
+{
+	chr *cp;
+	chr *realmin = (min == v->stop) ? min : min + 1;
+	chr *realmax = (max == v->stop) ? max : max + 1;
+	color co;
+	struct sset *css;
+	struct sset *ss;
+	struct colormap *cm = d->cm;
+
+	/* initialize */
+	css = initialize(v, d, start);
+	cp = start;
+	if (hitstopp != NULL)
+		*hitstopp = 0;
+
+	/* startup */
+	FDEBUG(("--- startup ---\n"));
+	if (cp == v->start) {
+		co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
+		FDEBUG(("color %ld\n", (long)co));
+	} else {
+		co = GETCOLOR(cm, *(cp - 1));
+		FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
+	}
+	css = miss(v, d, css, co, cp, start);
+	if (css == NULL)
+		return NULL;
+	css->lastseen = cp;
+	ss = css;
+
+	/* main loop */
+	if (v->eflags&REG_FTRACE)
+		while (cp < realmax) {
+			FDEBUG(("--- at c%d ---\n", css - d->ssets));
+			co = GETCOLOR(cm, *cp);
+			FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
+			ss = css->outs[co];
+			if (ss == NULL) {
+				ss = miss(v, d, css, co, cp+1, start);
+				if (ss == NULL)
+					break;	/* NOTE BREAK OUT */
+			}
+			cp++;
+			ss->lastseen = cp;
+			css = ss;
+			if ((ss->flags&POSTSTATE) && cp >= realmin)
+				break;		/* NOTE BREAK OUT */
+		}
+	else
+		while (cp < realmax) {
+			co = GETCOLOR(cm, *cp);
+			ss = css->outs[co];
+			if (ss == NULL) {
+				ss = miss(v, d, css, co, cp+1, start);
+				if (ss == NULL)
+					break;	/* NOTE BREAK OUT */
+			}
+			cp++;
+			ss->lastseen = cp;
+			css = ss;
+			if ((ss->flags&POSTSTATE) && cp >= realmin)
+				break;		/* NOTE BREAK OUT */
+		}
+
+	if (ss == NULL)
+		return NULL;
+
+	if (coldp != NULL)	/* report last no-progress state set, if any */
+		*coldp = lastcold(v, d);
+
+	if ((ss->flags&POSTSTATE) && cp > min) {
+		assert(cp >= realmin);
+		cp--;
+	} else if (cp == v->stop && max == v->stop) {
+		co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
+		FDEBUG(("color %ld\n", (long)co));
+		ss = miss(v, d, css, co, cp, start);
+		/* match might have ended at eol */
+		if ((ss == NULL || !(ss->flags&POSTSTATE)) && hitstopp != NULL)
+			*hitstopp = 1;
+	}
+
+	if (ss == NULL || !(ss->flags&POSTSTATE))
+		return NULL;
+
+	return cp;
+}
+
+/*
+ - lastcold - determine last point at which no progress had been made
+ ^ static chr *lastcold(struct vars *, struct dfa *);
+ */
+static chr *			/* endpoint, or NULL */
+lastcold(v, d)
+struct vars *v;
+struct dfa *d;
+{
+	struct sset *ss;
+	chr *nopr;
+	int i;
+
+	nopr = d->lastnopr;
+	if (nopr == NULL)
+		nopr = v->start;
+	for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
+		if ((ss->flags&NOPROGRESS) && nopr < ss->lastseen)
+			nopr = ss->lastseen;
+	return nopr;
+}
+
+/*
+ - newdfa - set up a fresh DFA
+ ^ static struct dfa *newdfa(struct vars *, struct cnfa *,
+ ^ 	struct colormap *, struct smalldfa *);
+ */
+static struct dfa *
+newdfa(v, cnfa, cm, small)
+struct vars *v;
+struct cnfa *cnfa;
+struct colormap *cm;
+struct smalldfa *small;		/* preallocated space, may be NULL */
+{
+	struct dfa *d;
+	size_t nss = cnfa->nstates * 2;
+	int wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
+	struct smalldfa *smallwas = small;
+
+	assert(cnfa != NULL && cnfa->nstates != 0);
+
+	if (nss <= FEWSTATES && cnfa->ncolors <= FEWCOLORS) {
+		assert(wordsper == 1);
+		if (small == NULL) {
+			small = (struct smalldfa *)MALLOC(
+						sizeof(struct smalldfa));
+			if (small == NULL) {
+				ERR(REG_ESPACE);
+				return NULL;
+			}
+		}
+		d = &small->dfa;
+		d->ssets = small->ssets;
+		d->statesarea = small->statesarea;
+		d->work = &d->statesarea[nss];
+		d->outsarea = small->outsarea;
+		d->incarea = small->incarea;
+		d->cptsmalloced = 0;
+		d->mallocarea = (smallwas == NULL) ? (char *)small : NULL;
+	} else {
+		d = (struct dfa *)MALLOC(sizeof(struct dfa));
+		if (d == NULL) {
+			ERR(REG_ESPACE);
+			return NULL;
+		}
+		d->ssets = (struct sset *)MALLOC(nss * sizeof(struct sset));
+		d->statesarea = (unsigned *)MALLOC((nss+WORK) * wordsper *
+							sizeof(unsigned));
+		d->work = &d->statesarea[nss * wordsper];
+		d->outsarea = (struct sset **)MALLOC(nss * cnfa->ncolors *
+							sizeof(struct sset *));
+		d->incarea = (struct arcp *)MALLOC(nss * cnfa->ncolors *
+							sizeof(struct arcp));
+		d->cptsmalloced = 1;
+		d->mallocarea = (char *)d;
+		if (d->ssets == NULL || d->statesarea == NULL ||
+				d->outsarea == NULL || d->incarea == NULL) {
+			freedfa(d);
+			ERR(REG_ESPACE);
+			return NULL;
+		}
+	}
+
+	d->nssets = (v->eflags&REG_SMALL) ? 7 : nss;
+	d->nssused = 0;
+	d->nstates = cnfa->nstates;
+	d->ncolors = cnfa->ncolors;
+	d->wordsper = wordsper;
+	d->cnfa = cnfa;
+	d->cm = cm;
+	d->lastpost = NULL;
+	d->lastnopr = NULL;
+	d->search = d->ssets;
+
+	/* initialization of sset fields is done as needed */
+
+	return d;
+}
+
+/*
+ - freedfa - free a DFA
+ ^ static VOID freedfa(struct dfa *);
+ */
+static VOID
+freedfa(d)
+struct dfa *d;
+{
+	if (d->cptsmalloced) {
+		if (d->ssets != NULL)
+			FREE(d->ssets);
+		if (d->statesarea != NULL)
+			FREE(d->statesarea);
+		if (d->outsarea != NULL)
+			FREE(d->outsarea);
+		if (d->incarea != NULL)
+			FREE(d->incarea);
+	}
+
+	if (d->mallocarea != NULL)
+		FREE(d->mallocarea);
+}
+
+/*
+ - hash - construct a hash code for a bitvector
+ * There are probably better ways, but they're more expensive.
+ ^ static unsigned hash(unsigned *, int);
+ */
+static unsigned
+hash(uv, n)
+unsigned *uv;
+int n;
+{
+	int i;
+	unsigned h;
+
+	h = 0;
+	for (i = 0; i < n; i++)
+		h ^= uv[i];
+	return h;
+}
+
+/*
+ - initialize - hand-craft a cache entry for startup, otherwise get ready
+ ^ static struct sset *initialize(struct vars *, struct dfa *, chr *);
+ */
+static struct sset *
+initialize(v, d, start)
+struct vars *v;			/* used only for debug flags */
+struct dfa *d;
+chr *start;
+{
+	struct sset *ss;
+	int i;
+
+	/* is previous one still there? */
+	if (d->nssused > 0 && (d->ssets[0].flags&STARTER))
+		ss = &d->ssets[0];
+	else {				/* no, must (re)build it */
+		ss = getvacant(v, d, start, start);
+		for (i = 0; i < d->wordsper; i++)
+			ss->states[i] = 0;
+		BSET(ss->states, d->cnfa->pre);
+		ss->hash = HASH(ss->states, d->wordsper);
+		assert(d->cnfa->pre != d->cnfa->post);
+		ss->flags = STARTER|LOCKED|NOPROGRESS;
+		/* lastseen dealt with below */
+	}
+
+	for (i = 0; i < d->nssused; i++)
+		d->ssets[i].lastseen = NULL;
+	ss->lastseen = start;		/* maybe untrue, but harmless */
+	d->lastpost = NULL;
+	d->lastnopr = NULL;
+	return ss;
+}
+
+/*
+ - miss - handle a cache miss
+ ^ static struct sset *miss(struct vars *, struct dfa *, struct sset *,
+ ^ 	pcolor, chr *, chr *);
+ */
+static struct sset *		/* NULL if goes to empty set */
+miss(v, d, css, co, cp, start)
+struct vars *v;			/* used only for debug flags */
+struct dfa *d;
+struct sset *css;
+pcolor co;
+chr *cp;			/* next chr */
+chr *start;			/* where the attempt got started */
+{
+	struct cnfa *cnfa = d->cnfa;
+	int i;
+	unsigned h;
+	struct carc *ca;
+	struct sset *p;
+	int ispost;
+	int noprogress;
+	int gotstate;
+	int dolacons;
+	int sawlacons;
+
+	/* for convenience, we can be called even if it might not be a miss */
+	if (css->outs[co] != NULL) {
+		FDEBUG(("hit\n"));
+		return css->outs[co];
+	}
+	FDEBUG(("miss\n"));
+
+	/* first, what set of states would we end up in? */
+	for (i = 0; i < d->wordsper; i++)
+		d->work[i] = 0;
+	ispost = 0;
+	noprogress = 1;
+	gotstate = 0;
+	for (i = 0; i < d->nstates; i++)
+		if (ISBSET(css->states, i))
+			for (ca = cnfa->states[i]+1; ca->co != COLORLESS; ca++)
+				if (ca->co == co) {
+					BSET(d->work, ca->to);
+					gotstate = 1;
+					if (ca->to == cnfa->post)
+						ispost = 1;
+					if (!cnfa->states[ca->to]->co)
+						noprogress = 0;
+					FDEBUG(("%d -> %d\n", i, ca->to));
+				}
+	dolacons = (gotstate) ? (cnfa->flags&HASLACONS) : 0;
+	sawlacons = 0;
+	while (dolacons) {		/* transitive closure */
+		dolacons = 0;
+		for (i = 0; i < d->nstates; i++)
+			if (ISBSET(d->work, i))
+				for (ca = cnfa->states[i]+1; ca->co != COLORLESS;
+									ca++) {
+					if (ca->co <= cnfa->ncolors)
+						continue; /* NOTE CONTINUE */
+					sawlacons = 1;
+					if (ISBSET(d->work, ca->to))
+						continue; /* NOTE CONTINUE */
+					if (!lacon(v, cnfa, cp, ca->co))
+						continue; /* NOTE CONTINUE */
+					BSET(d->work, ca->to);
+					dolacons = 1;
+					if (ca->to == cnfa->post)
+						ispost = 1;
+					if (!cnfa->states[ca->to]->co)
+						noprogress = 0;
+					FDEBUG(("%d :> %d\n", i, ca->to));
+				}
+	}
+	if (!gotstate)
+		return NULL;
+	h = HASH(d->work, d->wordsper);
+
+	/* next, is that in the cache? */
+	for (p = d->ssets, i = d->nssused; i > 0; p++, i--)
+		if (HIT(h, d->work, p, d->wordsper)) {
+			FDEBUG(("cached c%d\n", p - d->ssets));
+			break;			/* NOTE BREAK OUT */
+		}
+	if (i == 0) {		/* nope, need a new cache entry */
+		p = getvacant(v, d, cp, start);
+		assert(p != css);
+		for (i = 0; i < d->wordsper; i++)
+			p->states[i] = d->work[i];
+		p->hash = h;
+		p->flags = (ispost) ? POSTSTATE : 0;
+		if (noprogress)
+			p->flags |= NOPROGRESS;
+		/* lastseen to be dealt with by caller */
+	}
+
+	if (!sawlacons) {		/* lookahead conds. always cache miss */
+		FDEBUG(("c%d[%d]->c%d\n", css - d->ssets, co, p - d->ssets));
+		css->outs[co] = p;
+		css->inchain[co] = p->ins;
+		p->ins.ss = css;
+		p->ins.co = (color)co;
+	}
+	return p;
+}
+
+/*
+ - lacon - lookahead-constraint checker for miss()
+ ^ static int lacon(struct vars *, struct cnfa *, chr *, pcolor);
+ */
+static int			/* predicate:  constraint satisfied? */
+lacon(v, pcnfa, cp, co)
+struct vars *v;
+struct cnfa *pcnfa;		/* parent cnfa */
+chr *cp;
+pcolor co;			/* "color" of the lookahead constraint */
+{
+	int n;
+	struct subre *sub;
+	struct dfa *d;
+	struct smalldfa sd;
+	chr *end;
+
+	n = co - pcnfa->ncolors;
+	assert(n < v->g->nlacons && v->g->lacons != NULL);
+	FDEBUG(("=== testing lacon %d\n", n));
+	sub = &v->g->lacons[n];
+	d = newdfa(v, &sub->cnfa, &v->g->cmap, &sd);
+	if (d == NULL) {
+		ERR(REG_ESPACE);
+		return 0;
+	}
+	end = longest(v, d, cp, v->stop, (int *)NULL);
+	freedfa(d);
+	FDEBUG(("=== lacon %d match %d\n", n, (end != NULL)));
+	return (sub->subno) ? (end != NULL) : (end == NULL);
+}
+
+/*
+ - getvacant - get a vacant state set
+ * This routine clears out the inarcs and outarcs, but does not otherwise
+ * clear the innards of the state set -- that's up to the caller.
+ ^ static struct sset *getvacant(struct vars *, struct dfa *, chr *, chr *);
+ */
+static struct sset *
+getvacant(v, d, cp, start)
+struct vars *v;			/* used only for debug flags */
+struct dfa *d;
+chr *cp;
+chr *start;
+{
+	int i;
+	struct sset *ss;
+	struct sset *p;
+	struct arcp ap;
+	struct arcp lastap;
+	color co;
+
+	ss = pickss(v, d, cp, start);
+	assert(!(ss->flags&LOCKED));
+
+	/* clear out its inarcs, including self-referential ones */
+	ap = ss->ins;
+	while ((p = ap.ss) != NULL) {
+		co = ap.co;
+		FDEBUG(("zapping c%d's %ld outarc\n", p - d->ssets, (long)co));
+		p->outs[co] = NULL;
+		ap = p->inchain[co];
+		p->inchain[co].ss = NULL;	/* paranoia */
+	}
+	ss->ins.ss = NULL;
+
+	/* take it off the inarc chains of the ssets reached by its outarcs */
+	for (i = 0; i < d->ncolors; i++) {
+		p = ss->outs[i];
+		assert(p != ss);		/* not self-referential */
+		if (p == NULL)
+			continue;		/* NOTE CONTINUE */
+		FDEBUG(("del outarc %d from c%d's in chn\n", i, p - d->ssets));
+		if (p->ins.ss == ss && p->ins.co == i)
+			p->ins = ss->inchain[i];
+		else {
+			assert(p->ins.ss != NULL);
+			for (ap = p->ins; ap.ss != NULL &&
+						!(ap.ss == ss && ap.co == i);
+						ap = ap.ss->inchain[ap.co])
+				lastap = ap;
+			assert(ap.ss != NULL);
+			lastap.ss->inchain[lastap.co] = ss->inchain[i];
+		}
+		ss->outs[i] = NULL;
+		ss->inchain[i].ss = NULL;
+	}
+
+	/* if ss was a success state, may need to remember location */
+	if ((ss->flags&POSTSTATE) && ss->lastseen != d->lastpost &&
+			(d->lastpost == NULL || d->lastpost < ss->lastseen))
+		d->lastpost = ss->lastseen;
+
+	/* likewise for a no-progress state */
+	if ((ss->flags&NOPROGRESS) && ss->lastseen != d->lastnopr &&
+			(d->lastnopr == NULL || d->lastnopr < ss->lastseen))
+		d->lastnopr = ss->lastseen;
+
+	return ss;
+}
+
+/*
+ - pickss - pick the next stateset to be used
+ ^ static struct sset *pickss(struct vars *, struct dfa *, chr *, chr *);
+ */
+static struct sset *
+pickss(v, d, cp, start)
+struct vars *v;			/* used only for debug flags */
+struct dfa *d;
+chr *cp;
+chr *start;
+{
+	int i;
+	struct sset *ss;
+	struct sset *end;
+	chr *ancient;
+
+	/* shortcut for cases where cache isn't full */
+	if (d->nssused < d->nssets) {
+		i = d->nssused;
+		d->nssused++;
+		ss = &d->ssets[i];
+		FDEBUG(("new c%d\n", i));
+		/* set up innards */
+		ss->states = &d->statesarea[i * d->wordsper];
+		ss->flags = 0;
+		ss->ins.ss = NULL;
+		ss->ins.co = WHITE;		/* give it some value */
+		ss->outs = &d->outsarea[i * d->ncolors];
+		ss->inchain = &d->incarea[i * d->ncolors];
+		for (i = 0; i < d->ncolors; i++) {
+			ss->outs[i] = NULL;
+			ss->inchain[i].ss = NULL;
+		}
+		return ss;
+	}
+
+	/* look for oldest, or old enough anyway */
+	if (cp - start > d->nssets*2/3)		/* oldest 33% are expendable */
+		ancient = cp - d->nssets*2/3;
+	else
+		ancient = start;
+	for (ss = d->search, end = &d->ssets[d->nssets]; ss < end; ss++)
+		if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
+							!(ss->flags&LOCKED)) {
+			d->search = ss + 1;
+			FDEBUG(("replacing c%d\n", ss - d->ssets));
+			return ss;
+		}
+	for (ss = d->ssets, end = d->search; ss < end; ss++)
+		if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
+							!(ss->flags&LOCKED)) {
+			d->search = ss + 1;
+			FDEBUG(("replacing c%d\n", ss - d->ssets));
+			return ss;
+		}
+
+	/* nobody's old enough?!? -- something's really wrong */
+	FDEBUG(("can't find victim to replace!\n"));
+	assert(NOTREACHED);
+	ERR(REG_ASSERT);
+	return d->ssets;
+}
+
+/* End of rege_dfa.c */