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Overview
Comment:[1080042][8f245009b0] Big bundle of regexp engine fixes and improvements contributed from Tom Lane of the postgres project.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 497b93405b3435aa98b1a1bc243b0b70e5f89192
User & Date: dgp 2015-10-21 14:10:13
Context
2016-04-19
20:35
Fork of Tcl used in the "Little" project. http://www.mcvoy.com/lm/little/index.html check-in: 69b737f5a1 user: dgp tags: little
2015-10-23
08:13
Merge trunk check-in: d68de1f600 user: jan.nijtmans tags: androwish
08:12
Change "clock scan/format -format %x -locale current" output on msgcat locale change. Bug [4a0c163d2... check-in: 5855bdf4a8 user: oehhar tags: trunk
2015-10-21
23:30
Micro-optimization: remove double checked lock from TclGetAllocCache in favour of initialization in ... check-in: fdbf64dc50 user: kbk tags: drh-micro-optimization
20:30
Change "clock format -format %x -locale current" output on msgcat locale change [4a0c163d24] check-in: e5bf4e6084 user: oehhar tags: bug-4a0c163d24
17:02
Merge updates from trunk. check-in: 6e776b8e33 user: mistachkin tags: tip-435, bug-57945b574a
14:10
[1080042][8f245009b0] Big bundle of regexp engine fixes and improvements contributed from Tom Lane o... check-in: 497b93405b user: dgp tags: trunk
13:50
[1080042][8f245009b0] Big bundle of regexp engine fixes and improvements contributed from Tom Lane o... check-in: 01bd72a637 user: dgp tags: core-8-5-branch
2015-10-19
14:07
[154f0982f2] Document that Tcl_NewObjectInstance() really needs to make a namespace. check-in: 2327af6915 user: dkf tags: trunk
Changes
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 *
 * One or two things that technically ought to be in here are actually in
 * color.c, thanks to some incestuous relationships in the color chains.
 */

#define	NISERR()	VISERR(nfa->v)
#define	NERR(e)		VERR(nfa->v, (e))



 
/*
 - newnfa - set up an NFA
 ^ static struct nfa *newnfa(struct vars *, struct colormap *, struct nfa *);
 */
static struct nfa *		/* the NFA, or NULL */
newnfa(
................................................................................

    nfa->states = NULL;
    nfa->slast = NULL;
    nfa->free = NULL;
    nfa->nstates = 0;
    nfa->cm = cm;
    nfa->v = v;
    nfa->size = 0;
    nfa->bos[0] = nfa->bos[1] = COLORLESS;
    nfa->eos[0] = nfa->eos[1] = COLORLESS;
    nfa->parent = parent;	/* Precedes newfstate so parent is valid. */
    nfa->post = newfstate(nfa, '@');	/* number 0 */
    nfa->pre = newfstate(nfa, '>');	/* number 1 */

    nfa->init = newstate(nfa);	/* May become invalid later. */
................................................................................

    if (ISERR()) {
	freenfa(nfa);
	return NULL;
    }
    return nfa;
}
 
/*
 - TooManyStates - checks if the max states exceeds the compile-time value
 ^ static int TooManyStates(struct nfa *);
 */
static int
TooManyStates(
    struct nfa *nfa)
{
    struct nfa *parent = nfa->parent;
    size_t sz = nfa->size;

    while (parent != NULL) {
	sz = parent->size;
	parent = parent->parent;
    }
    if (sz > REG_MAX_STATES) {
	return 1;
    }
    return 0;
}
 
/*
 - IncrementSize - increases the tracked size of the NFA and its parents.
 ^ static void IncrementSize(struct nfa *);
 */
static void
IncrementSize(
    struct nfa *nfa)
{
    struct nfa *parent = nfa->parent;

    nfa->size++;
    while (parent != NULL) {
	parent->size++;
	parent = parent->parent;
    }
}
 
/*
 - DecrementSize - increases the tracked size of the NFA and its parents.
 ^ static void DecrementSize(struct nfa *);
 */
static void
DecrementSize(
    struct nfa *nfa)
{
    struct nfa *parent = nfa->parent;

    nfa->size--;
    while (parent != NULL) {
	parent->size--;
	parent = parent->parent;
    }
}
 
/*
 - freenfa - free an entire NFA
 ^ static void freenfa(struct nfa *);
 */
static void
freenfa(
................................................................................
 */
static struct state *		/* NULL on error */
newstate(
    struct nfa *nfa)
{
    struct state *s;

    if (TooManyStates(nfa)) {
	/* XXX: add specific error for this */
	NERR(REG_ETOOBIG);
	return NULL;
    }
    if (nfa->free != NULL) {
	s = nfa->free;
	nfa->free = s->next;
    } else {




	s = (struct state *) MALLOC(sizeof(struct state));
	if (s == NULL) {
	    NERR(REG_ESPACE);
	    return NULL;
	}

	s->oas.next = NULL;
	s->free = NULL;
	s->noas = 0;
    }

    assert(nfa->nstates >= 0);
    s->no = nfa->nstates++;
................................................................................
    s->next = NULL;
    if (nfa->slast != NULL) {
	assert(nfa->slast->next == NULL);
	nfa->slast->next = s;
    }
    s->prev = nfa->slast;
    nfa->slast = s;

    /*
     * Track the current size and the parent size.
     */

    IncrementSize(nfa);
    return s;
}
 
/*
 - newfstate - allocate an NFA state with a specified flag value
 ^ static struct state *newfstate(struct nfa *, int flag);
 */
................................................................................
    } else {
	assert(s == nfa->states);
	nfa->states = s->next;
    }
    s->prev = NULL;
    s->next = nfa->free;	/* don't delete it, put it on the free list */
    nfa->free = s;
    DecrementSize(nfa);
}
 
/*
 - destroystate - really get rid of an already-freed state
 ^ static void destroystate(struct nfa *, struct state *);
 */
static void
................................................................................
    struct arcbatch *ab;
    struct arcbatch *abnext;

    assert(s->no == FREESTATE);
    for (ab=s->oas.next ; ab!=NULL ; ab=abnext) {
	abnext = ab->next;
	FREE(ab);

    }
    s->ins = NULL;
    s->outs = NULL;
    s->next = NULL;
    FREE(s);

}
 
/*
 - newarc - set up a new arc within an NFA
 ^ static void newarc(struct nfa *, int, pcolor, struct state *,
 ^	struct state *);
 */




static void
newarc(
    struct nfa *nfa,
    int t,
    pcolor co,
    struct state *from,
    struct state *to)
{
    struct arc *a;

    assert(from != NULL && to != NULL);

    /*
     * Check for duplicates.
     */





    for (a=from->outs ; a!=NULL ; a=a->outchain) {



	if (a->to == to && a->co == co && a->type == t) {
	    return;
	}
    }























    a = allocarc(nfa, from);
    if (NISERR()) {
	return;
    }
    assert(a != NULL);

    a->type = t;
    a->co = (color) co;
    a->to = to;
    a->from = from;

    /*
     * Put the new arc on the beginning, not the end, of the chains. Not only
     * is this easier, it has the very useful side effect that deleting the
     * most-recently-added arc is the cheapest case rather than the most
     * expensive one.
     */

    a->inchain = to->ins;




    to->ins = a;
    a->outchain = from->outs;




    from->outs = a;

    from->nouts++;
    to->nins++;

    if (COLORED(a) && nfa->parent == NULL) {
	colorchain(nfa->cm, a);
................................................................................
    }

    /*
     * if none at hand, get more
     */

    if (s->free == NULL) {
	struct arcbatch *newAb = (struct arcbatch *)
		MALLOC(sizeof(struct arcbatch));
	int i;






	if (newAb == NULL) {
	    NERR(REG_ESPACE);
	    return NULL;
	}

	newAb->next = s->oas.next;
	s->oas.next = newAb;

	for (i=0 ; i<ABSIZE ; i++) {
	    newAb->a[i].type = 0;
	    newAb->a[i].freechain = &newAb->a[i+1];
	}
................................................................................
static void
freearc(
    struct nfa *nfa,
    struct arc *victim)
{
    struct state *from = victim->from;
    struct state *to = victim->to;
    struct arc *a;

    assert(victim->type != 0);

    /*
     * Take it off color chain if necessary.
     */

................................................................................
    }

    /*
     * Take it off source's out-chain.
     */

    assert(from != NULL);
    assert(from->outs != NULL);

    a = from->outs;
    if (a == victim) {		/* simple case: first in chain */
	from->outs = victim->outchain;
    } else {
	for (; a!=NULL && a->outchain!=victim ; a=a->outchain) {
	    continue;
	}
	assert(a != NULL);

	a->outchain = victim->outchain;
    }
    from->nouts--;

    /*
     * Take it off target's in-chain.
     */

    assert(to != NULL);


    assert(to->ins != NULL);
    a = to->ins;
    if (a == victim) {		/* simple case: first in chain */
	to->ins = victim->inchain;
    } else {
	for (; a->inchain!=victim ; a=a->inchain) {
	    assert(a->inchain != NULL);
	    continue;
	}
	a->inchain = victim->inchain;


    }
    to->nins--;

    /*
     * Clean up and place on free list.
     */

    victim->type = 0;
    victim->from = NULL;	/* precautions... */
    victim->to = NULL;
    victim->inchain = NULL;

    victim->outchain = NULL;

    victim->freechain = from->free;
    from->free = victim;
}












































 
/*
 - hasnonemptyout - Does state have a non-EMPTY out arc?
 ^ static int hasnonemptyout(struct state *);
 */
static int
hasnonemptyout(
................................................................................
    for (a = s->outs; a != NULL; a = a->outchain) {
	if (a->type != EMPTY) {
	    return 1;
	}
    }
    return 0;
}
 
/*
 - nonemptyouts - count non-EMPTY out arcs of a state
 ^ static int nonemptyouts(struct state *);
 */
static int
nonemptyouts(
    struct state *s)
{
    int n = 0;
    struct arc *a;

    for (a = s->outs; a != NULL; a = a->outchain) {
	if (a->type != EMPTY) {
	    n++;
	}
    }
    return n;
}
 
/*
 - nonemptyins - count non-EMPTY in arcs of a state
 ^ static int nonemptyins(struct state *);
 */
static int
nonemptyins(
    struct state *s)
{
    int n = 0;
    struct arc *a;

    for (a = s->ins; a != NULL; a = a->inchain) {
	if (a->type != EMPTY) {
	    n++;
	}
    }
    return n;
}
 
/*
 - findarc - find arc, if any, from given source with given type and color
 * If there is more than one such arc, the result is random.
 ^ static struct arc *findarc(struct state *, int, pcolor);
 */
static struct arc *
................................................................................
    struct nfa *nfa,
    struct arc *oa,
    struct state *from,
    struct state *to)
{
    newarc(nfa, oa->type, oa->co, from, to);
}
 
/*



































































































































































 - moveins - move all in arcs of a state to another state
 * You might think this could be done better by just updating the
 * existing arcs, and you would be right if it weren't for the desire
 * for duplicate suppression, which makes it easier to just make new
 * ones to exploit the suppression built into newarc.





 ^ static void moveins(struct nfa *, struct state *, struct state *);
 */
static void
moveins(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState)
{




    struct arc *a;
























    assert(oldState != newState);



    while ((a = oldState->ins) != NULL) {













	cparc(nfa, a, a->from, newState);






	freearc(nfa, a);







    }










    assert(oldState->nins == 0);
    assert(oldState->ins == NULL);
}
 
/*
 - copyins - copy in arcs of a state to another state
 * Either all arcs, or only non-empty ones as determined by all value.
 ^ static VOID copyins(struct nfa *, struct state *, struct state *, int);
 */
static void
copyins(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState,
    int all)
{




    struct arc *a;























    assert(oldState != newState);



    for (a=oldState->ins ; a!=NULL ; a=a->inchain) {
	if (all || a->type != EMPTY) {
	    cparc(nfa, a, a->from, newState);



	}

















    }
}



 






/*

































































































 - moveouts - move all out arcs of a state to another state
 ^ static void moveouts(struct nfa *, struct state *, struct state *);
 */
static void
moveouts(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState)
{




    struct arc *a;
























    assert(oldState != newState);



    while ((a = oldState->outs) != NULL) {









	cparc(nfa, a, newState, a->to);






	freearc(nfa, a);







    }
}



 










/*
 - copyouts - copy out arcs of a state to another state
 * Either all arcs, or only non-empty ones as determined by all value.
 ^ static VOID copyouts(struct nfa *, struct state *, struct state *, int);
 */
static void
copyouts(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState,
    int all)
{




    struct arc *a;























    assert(oldState != newState);



    for (a=oldState->outs ; a!=NULL ; a=a->outchain) {
	if (all || a->type != EMPTY) {








	    cparc(nfa, a, newState, a->to);












	}








    }
}
 
/*
 - cloneouts - copy out arcs of a state to another state pair, modifying type
 ^ static void cloneouts(struct nfa *, struct state *, struct state *,
 ^ 	struct state *, int);
................................................................................
    }
}
 
/*
 - optimize - optimize an NFA
 ^ static long optimize(struct nfa *, FILE *);
 */














static long			/* re_info bits */
optimize(
    struct nfa *nfa,
    FILE *f)			/* for debug output; NULL none */
{
    int verbose = (f != NULL) ? 1 : 0;

................................................................................
    if (verbose) {
	fprintf(f, "\nempties:\n");
    }
    fixempties(nfa, f);		/* get rid of EMPTY arcs */
    if (verbose) {
	fprintf(f, "\nconstraints:\n");
    }

    pullback(nfa, f);		/* pull back constraints backward */
    pushfwd(nfa, f);		/* push fwd constraints forward */
    if (verbose) {
	fprintf(f, "\nfinal cleanup:\n");
    }
    cleanup(nfa);		/* final tidying */





    return analyze(nfa);	/* and analysis */
}
 
/*
 - pullback - pull back constraints backward to (with luck) eliminate them
 ^ static void pullback(struct nfa *, FILE *);
 */
static void
pullback(
    struct nfa *nfa,
    FILE *f)			/* for debug output; NULL none */
{
    struct state *s;
    struct state *nexts;
    struct arc *a;
    struct arc *nexta;

    int progress;

    /*
     * Find and pull until there are no more.
     */

    do {
	progress = 0;
	for (s=nfa->states ; s!=NULL && !NISERR() ; s=nexts) {
	    nexts = s->next;

	    for (a=s->outs ; a!=NULL && !NISERR() ; a=nexta) {
		nexta = a->outchain;
		if (a->type == '^' || a->type == BEHIND) {
		    if (pull(nfa, a)) {
			progress = 1;
		    }
		}
		assert(nexta == NULL || s->no != FREESTATE);











	    }
	}
	if (progress && f != NULL) {
	    dumpnfa(nfa, f);
	}
    } while (progress && !NISERR());
    if (NISERR()) {
	return;
    }







    for (a=nfa->pre->outs ; a!=NULL ; a=nexta) {
	nexta = a->outchain;
	if (a->type == '^') {
	    assert(a->co == 0 || a->co == 1);
	    newarc(nfa, PLAIN, nfa->bos[a->co], a->from, a->to);
	    freearc(nfa, a);
	}
    }
}
 
/*
 - pull - pull a back constraint backward past its source state




 * A significant property of this function is that it deletes at most
 * one state -- the constraint's from state -- and only if the constraint
 * was that state's last outarc.









 ^ static int pull(struct nfa *, struct arc *);
 */
static int			/* 0 couldn't, 1 could */
pull(
    struct nfa *nfa,
    struct arc *con)

{
    struct state *from = con->from;
    struct state *to = con->to;
    struct arc *a;
    struct arc *nexta;
    struct state *s;

    if (from == to) {		/* circular constraint is pointless */
	freearc(nfa, con);
	return 1;
    }
    if (from->flag) {		/* can't pull back beyond start */
	return 0;
    }
    if (from->nins == 0) {	/* unreachable */
	freearc(nfa, con);
	return 1;
    }

    /*
     * DGP 2007-11-15: Cloning a state with a circular constraint on its list
     * of outs can lead to trouble [Bug 1810038], so get rid of them first.
     */

    for (a = from->outs; a != NULL; a = nexta) {
	nexta = a->outchain;
	switch (a->type) {
	case '^':
	case '$':
	case BEHIND:
	case AHEAD:
	    if (from == a->to) {
		freearc(nfa, a);
	    }
	    break;
	}
    }

    /*
     * First, clone from state if necessary to avoid other outarcs.


     */

    if (from->nouts > 1) {
	s = newstate(nfa);
	if (NISERR()) {
	    return 0;
	}
	assert(to != from);		/* con is not an inarc */
	copyins(nfa, from, s, 1);	/* duplicate inarcs */
	cparc(nfa, con, s, to);		/* move constraint arc */
	freearc(nfa, con);



	from = s;
	con = from->outs;
    }
    assert(from->nouts == 1);

    /*
     * Propagate the constraint into the from state's inarcs.
     */

    for (a=from->ins ; a!=NULL ; a=nexta) {
	nexta = a->inchain;
	switch (combine(con, a)) {
	case INCOMPATIBLE:	/* destroy the arc */
	    freearc(nfa, a);
	    break;
	case SATISFIED:		/* no action needed */
	    break;
	case COMPATIBLE:	/* swap the two arcs, more or less */








	    s = newstate(nfa);
	    if (NISERR()) {
		return 0;
	    }
	    cparc(nfa, a, s, to);	/* anticipate move */
	    cparc(nfa, con, a->from, s);
	    if (NISERR()) {
		return 0;


	    }


	    freearc(nfa, a);
	    break;
	default:
	    assert(NOTREACHED);
	    break;
	}
    }

    /*
     * Remaining inarcs, if any, incorporate the constraint.
     */

    moveins(nfa, from, to);
    dropstate(nfa, from);	/* will free the constraint */

    return 1;
}
 
/*
 - pushfwd - push forward constraints forward to (with luck) eliminate them
 ^ static void pushfwd(struct nfa *, FILE *);
 */
static void
pushfwd(
    struct nfa *nfa,
    FILE *f)			/* for debug output; NULL none */
{
    struct state *s;
    struct state *nexts;
    struct arc *a;
    struct arc *nexta;

    int progress;

    /*
     * Find and push until there are no more.
     */

    do {
	progress = 0;
	for (s=nfa->states ; s!=NULL && !NISERR() ; s=nexts) {
	    nexts = s->next;

	    for (a = s->ins; a != NULL && !NISERR(); a = nexta) {
		nexta = a->inchain;
		if (a->type == '$' || a->type == AHEAD) {
		    if (push(nfa, a)) {
			progress = 1;
		    }
		}
		assert(nexta == NULL || s->no != FREESTATE);











	    }
	}
	if (progress && f != NULL) {
	    dumpnfa(nfa, f);
	}
    } while (progress && !NISERR());
    if (NISERR()) {
	return;
    }







    for (a = nfa->post->ins; a != NULL; a = nexta) {
	nexta = a->inchain;
	if (a->type == '$') {
	    assert(a->co == 0 || a->co == 1);
	    newarc(nfa, PLAIN, nfa->eos[a->co], a->from, a->to);
	    freearc(nfa, a);
	}
    }
}
 
/*
 - push - push a forward constraint forward past its destination state




 * A significant property of this function is that it deletes at most
 * one state -- the constraint's to state -- and only if the constraint
 * was that state's last inarc.










 ^ static int push(struct nfa *, struct arc *);
 */
static int			/* 0 couldn't, 1 could */
push(
    struct nfa *nfa,
    struct arc *con)

{
    struct state *from = con->from;
    struct state *to = con->to;
    struct arc *a;
    struct arc *nexta;
    struct state *s;

    if (to == from) {		/* circular constraint is pointless */
	freearc(nfa, con);
	return 1;
    }
    if (to->flag) {		/* can't push forward beyond end */
	return 0;
    }
    if (to->nouts == 0) {	/* dead end */
	freearc(nfa, con);
	return 1;
    }

    /*
     * DGP 2007-11-15: Here we duplicate the same protections as appear
     * in pull() above to avoid troubles with cloning a state with a
     * circular constraint on its list of ins.  It is not clear whether
     * this is necessary, or is protecting against a "can't happen".
     * Any test case that actually leads to a freearc() call here would
     * be a welcome addition to the test suite.
     */

    for (a = to->ins; a != NULL; a = nexta) {
	nexta = a->inchain;
	switch (a->type) {
	case '^':
	case '$':
	case BEHIND:
	case AHEAD:
	    if (a->from == to) {
		freearc(nfa, a);
	    }
	    break;
	}
    }
    /*
     * First, clone to state if necessary to avoid other inarcs.


     */

    if (to->nins > 1) {
	s = newstate(nfa);
	if (NISERR()) {
	    return 0;
	}
	copyouts(nfa, to, s, 1);	/* duplicate outarcs */
	cparc(nfa, con, from, s);	/* move constraint */
	freearc(nfa, con);



	to = s;
	con = to->ins;
    }
    assert(to->nins == 1);

    /*
     * Propagate the constraint into the to state's outarcs.
     */

    for (a = to->outs; a != NULL; a = nexta) {
	nexta = a->outchain;
	switch (combine(con, a)) {
	case INCOMPATIBLE:	/* destroy the arc */
	    freearc(nfa, a);
	    break;
	case SATISFIED:		/* no action needed */
	    break;
	case COMPATIBLE:	/* swap the two arcs, more or less */








	    s = newstate(nfa);
	    if (NISERR()) {
		return 0;
	    }



	    cparc(nfa, con, s, a->to);	/* anticipate move */
	    cparc(nfa, a, from, s);
	    if (NISERR()) {
		return 0;
	    }
	    freearc(nfa, a);
	    break;
	default:
	    assert(NOTREACHED);
	    break;
	}
    }

    /*
     * Remaining outarcs, if any, incorporate the constraint.
     */

    moveouts(nfa, to, from);
    dropstate(nfa, to);		/* will free the constraint */

    return 1;
}
 
/*
 - combine - constraint lands on an arc, what happens?
 ^ #def	INCOMPATIBLE	1	// destroys arc
 ^ #def	SATISFIED	2	// constraint satisfied
................................................................................
    FILE *f)			/* for debug output; NULL none */
{
    struct state *s;
    struct state *s2;
    struct state *nexts;
    struct arc *a;
    struct arc *nexta;







    /*
     * First, get rid of any states whose sole out-arc is an EMPTY,
     * since they're basically just aliases for their successor.  The
     * parsing algorithm creates enough of these that it's worth
     * special-casing this.
     */
................................................................................
	    continue;
	}
	if (s != a->from) {
	    moveouts(nfa, s, a->from);
	}
	dropstate(nfa, s);
    }





    /*
     * For each remaining NFA state, find all other states that are
     * reachable from it by a chain of one or more EMPTY arcs.  Then
     * generate new arcs that eliminate the need for each such chain.
     *
     * If we just do this straightforwardly, the algorithm gets slow in
     * complex graphs, because the same arcs get copied to all
     * intermediate states of an EMPTY chain, and then uselessly pushed
     * repeatedly to the chain's final state; we waste a lot of time in
     * newarc's duplicate checking.  To improve matters, we decree that
     * any state with only EMPTY out-arcs is "doomed" and will not be
     * part of the final NFA. That can be ensured by not adding any new
     * out-arcs to such a state. Having ensured that, we need not update
     * the state's in-arcs list either; all arcs that might have gotten
     * pushed forward to it will just get pushed directly to successor
     * states.  This eliminates most of the useless duplicate arcs.






































     */









    for (s = nfa->states; s != NULL && !NISERR(); s = s->next) {
	for (s2 = emptyreachable(s, s); s2 != s && !NISERR();
		s2 = nexts) {




	    /*
	     * If s2 is doomed, we decide that (1) we will always push
	     * arcs forward to it, not pull them back to s; and (2) we
	     * can optimize away the push-forward, per comment above.
	     * So do nothing.




	     */










	    if (s2->flag || hasnonemptyout(s2)) {
		replaceempty(nfa, s, s2);

	    }











	    /* Reset the tmp fields as we walk back */
	    nexts = s2->tmp;
	    s2->tmp = NULL;
	}
	s->tmp = NULL;

    }


















    if (NISERR()) {
	return;
    }

    /*
     * Remove all the EMPTY arcs, since we don't need them anymore.
     */
................................................................................

    if (f != NULL) {
	dumpnfa(nfa, f);
    }
}
 
/*
 - emptyreachable - recursively find all states reachable from s by EMPTY arcs
 * The return value is the last such state found.  Its tmp field links back
 * to the next-to-last such state, and so on back to s, so that all these
 * states can be located without searching the whole NFA.





 * The maximum recursion depth here is equal to the length of the longest
 * loop-free chain of EMPTY arcs, which is surely no more than the size of
 * the NFA, and in practice will be a lot less than that.
 ^ static struct state *emptyreachable(struct state *, struct state *);
 */
static struct state *
emptyreachable(

    struct state *s,
    struct state *lastfound)

{
    struct arc *a;

    s->tmp = lastfound;
    lastfound = s;
    for (a = s->outs; a != NULL; a = a->outchain) {
	if (a->type == EMPTY && a->to->tmp == NULL) {
	    lastfound = emptyreachable(a->to, lastfound);
	}
    }
    return lastfound;
}
 
/*
 - replaceempty - replace an EMPTY arc chain with some non-empty arcs
 * The EMPTY arc(s) should be deleted later, but we can't do it here because
 * they may still be needed to identify other arc chains during fixempties().
 ^ static void replaceempty(struct nfa *, struct state *, struct state *);















 */





















static void
replaceempty(

    struct nfa *nfa,


    struct state *from,
    struct state *to)



{
    int fromouts;
    int toins;




















































































































    assert(from != to);







    /*
     * Create replacement arcs that bypass the need for the EMPTY chain.  We
     * can do this either by pushing arcs forward (linking directly from
     * "from"'s predecessors to "to") or by pulling them back (linking
     * directly from "from" to "to"'s successors).  In general, we choose
     * whichever way creates greater fan-out or fan-in, so as to improve the
     * odds of reducing the other state to zero in-arcs or out-arcs and
     * thereby being able to delete it.  However, if "from" is doomed (has no
     * non-EMPTY out-arcs), we must keep it so, so always push forward in that
     * case.


     *
     * The fan-out/fan-in comparison should count only non-EMPTY arcs.  If
     * "from" is doomed, we can skip counting "to"'s arcs, since we want to
     * force taking the copynonemptyins path in that case.

















































     */
    fromouts = nonemptyouts(from);
    toins = (fromouts == 0) ? 1 : nonemptyins(to);



    if (fromouts > toins) {
	copyouts(nfa, to, from, 0);































































	return;
    }
    if (fromouts < toins) {
	copyins(nfa, from, to, 0);





	return;
    }

    /*
     * fromouts == toins.  Decide on secondary issue: copy fewest arcs.



     *
     * Doesn't seem to be worth the trouble to exclude empties from these
     * comparisons; that takes extra time and doesn't seem to improve the
     * resulting graph much.








     */
    if (from->nins > to->nouts) {
	copyouts(nfa, to, from, 0);



































































	return;
    }

    copyins(nfa, from, to, 0);














































































































































































}
 
/*
 - cleanup - clean up NFA after optimizations
 ^ static void cleanup(struct nfa *);
 */
static void
................................................................................
	    }
	}
    }
    return 0;
}
 
/*
 - compact - compact an NFA
 ^ static void compact(struct nfa *, struct cnfa *);
 */
static void
compact(
    struct nfa *nfa,
    struct cnfa *cnfa)
{
................................................................................
		assert(s->no != cnfa->pre);
		ca->co = (color) (cnfa->ncolors + a->co);
		ca->to = a->to->no;
		ca++;
		cnfa->flags |= HASLACONS;
		break;
	    default:
		assert(NOTREACHED);
		break;
	    }
	}
	carcsort(first, ca-1);
	ca->co = COLORLESS;
	ca->to = 0;
	ca++;
    }
    assert(ca == &cnfa->arcs[narcs]);
    assert(cnfa->nstates != 0);

................................................................................
	cnfa->stflags[a->to->no] = CNFA_NOPROGRESS;
    }
    cnfa->stflags[nfa->pre->no] = CNFA_NOPROGRESS;
}
 
/*
 - carcsort - sort compacted-NFA arcs by color
 * Really dumb algorithm, but if the list is long enough for that to matter,
 * you're in real trouble anyway.
 ^ static void carcsort(struct carc *, struct carc *);
 */
static void
carcsort(
    struct carc *first,
    struct carc *last)
{
    struct carc *p;
    struct carc *q;
    struct carc tmp;

    if (last - first <= 1) {
	return;
    }




    for (p = first; p <= last; p++) {
	for (q = p; q <= last; q++) {

	    if (p->co > q->co || (p->co == q->co && p->to > q->to)) {
		assert(p != q);
		tmp = *p;

		*p = *q;
		*q = tmp;
	    }


	}


    }




}
 
/*
 - freecnfa - free a compacted NFA
 ^ static void freecnfa(struct cnfa *);
 */
static void
................................................................................
static void
dumpnfa(
    struct nfa *nfa,
    FILE *f)
{
#ifdef REG_DEBUG
    struct state *s;



    fprintf(f, "pre %d, post %d", nfa->pre->no, nfa->post->no);
    if (nfa->bos[0] != COLORLESS) {
	fprintf(f, ", bos [%ld]", (long) nfa->bos[0]);
    }
    if (nfa->bos[1] != COLORLESS) {
	fprintf(f, ", bol [%ld]", (long) nfa->bos[1]);
................................................................................
    }
    if (nfa->eos[1] != COLORLESS) {
	fprintf(f, ", eol [%ld]", (long) nfa->eos[1]);
    }
    fprintf(f, "\n");
    for (s = nfa->states; s != NULL; s = s->next) {
	dumpstate(s, f);


    }

    if (nfa->parent == NULL) {
	dumpcolors(nfa->cm, f);
    }
    fflush(f);
#endif
}
 
................................................................................
 */
static void
dumparcs(
    struct state *s,
    FILE *f)
{
    int pos;

    assert(s->nouts > 0);
    /* printing arcs in reverse order is usually clearer */
    pos = dumprarcs(s->outs, s, f, 1);
    if (pos != 1) {
	fprintf(f, "\n");
    }
}
 
/*
 - dumprarcs - dump remaining outarcs, recursively, in reverse order
 ^ static int dumprarcs(struct arc *, struct state *, FILE *, int);
 */
static int			/* resulting print position */
dumprarcs(
    struct arc *a,
    struct state *s,
    FILE *f,
    int pos)			/* initial print position */
{



    if (a->outchain != NULL) {
	pos = dumprarcs(a->outchain, s, f, pos);

    }


    dumparc(a, s, f);
    if (pos == 5) {
	fprintf(f, "\n");
	pos = 1;
    } else {
	pos++;
    }
    return pos;




}

 
/*
 - dumparc - dump one outarc in readable form, including prefixing tab
 ^ static void dumparc(struct arc *, struct state *, FILE *);
 */
static void
dumparc(






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30
31
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65
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90
91
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120
121
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127
128
129
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147
...
157
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159
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163






164
165
166
167
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169
170
...
227
228
229
230
231
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233

234
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...
245
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282

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333

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351
...
374
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382
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384
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400
...
415
416
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429
...
432
433
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436
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441

442
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461
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465
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520
521
522
523
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530
531
532
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534
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...
541
542
543
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546
547






































548
549
550
551
552
553
554
...
577
578
579
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581
582
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585
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731
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738
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833
834
835
836
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839
840
841
842
843
844
845

846
847
848
849
850
851
852

853
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865
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867
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887
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931
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938
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941
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961
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971
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978
979
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981
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986
987
988
989
990
991
992
993
994
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996
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1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
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1013
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1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
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1080
1081
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1087
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1089
1090
1091
1092
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1096
1097
1098
1099
1100
1101
1102

1103
1104
1105
1106
1107
1108
1109

1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143

1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
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1159
1160
1161
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1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
....
1385
1386
1387
1388
1389
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1397
1398
1399
1400
1401
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1408
1409
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1411
1412
....
1420
1421
1422
1423
1424
1425
1426
1427
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 *
 * One or two things that technically ought to be in here are actually in
 * color.c, thanks to some incestuous relationships in the color chains.
 */

#define	NISERR()	VISERR(nfa->v)
#define	NERR(e)		VERR(nfa->v, (e))
#define STACK_TOO_DEEP(x) (0)
#define CANCEL_REQUESTED(x) (0)
#define REG_CANCEL 777
 
/*
 - newnfa - set up an NFA
 ^ static struct nfa *newnfa(struct vars *, struct colormap *, struct nfa *);
 */
static struct nfa *		/* the NFA, or NULL */
newnfa(
................................................................................

    nfa->states = NULL;
    nfa->slast = NULL;
    nfa->free = NULL;
    nfa->nstates = 0;
    nfa->cm = cm;
    nfa->v = v;

    nfa->bos[0] = nfa->bos[1] = COLORLESS;
    nfa->eos[0] = nfa->eos[1] = COLORLESS;
    nfa->parent = parent;	/* Precedes newfstate so parent is valid. */
    nfa->post = newfstate(nfa, '@');	/* number 0 */
    nfa->pre = newfstate(nfa, '>');	/* number 1 */

    nfa->init = newstate(nfa);	/* May become invalid later. */
................................................................................

    if (ISERR()) {
	freenfa(nfa);
	return NULL;
    }
    return nfa;
}























































 
/*
 - freenfa - free an entire NFA
 ^ static void freenfa(struct nfa *);
 */
static void
freenfa(
................................................................................
 */
static struct state *		/* NULL on error */
newstate(
    struct nfa *nfa)
{
    struct state *s;






    if (nfa->free != NULL) {
	s = nfa->free;
	nfa->free = s->next;
    } else {
	if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE) {
	    NERR(REG_ETOOBIG);
	    return NULL;
	}
	s = (struct state *) MALLOC(sizeof(struct state));
	if (s == NULL) {
	    NERR(REG_ESPACE);
	    return NULL;
	}
	nfa->v->spaceused += sizeof(struct state);
	s->oas.next = NULL;
	s->free = NULL;
	s->noas = 0;
    }

    assert(nfa->nstates >= 0);
    s->no = nfa->nstates++;
................................................................................
    s->next = NULL;
    if (nfa->slast != NULL) {
	assert(nfa->slast->next == NULL);
	nfa->slast->next = s;
    }
    s->prev = nfa->slast;
    nfa->slast = s;






    return s;
}
 
/*
 - newfstate - allocate an NFA state with a specified flag value
 ^ static struct state *newfstate(struct nfa *, int flag);
 */
................................................................................
    } else {
	assert(s == nfa->states);
	nfa->states = s->next;
    }
    s->prev = NULL;
    s->next = nfa->free;	/* don't delete it, put it on the free list */
    nfa->free = s;

}
 
/*
 - destroystate - really get rid of an already-freed state
 ^ static void destroystate(struct nfa *, struct state *);
 */
static void
................................................................................
    struct arcbatch *ab;
    struct arcbatch *abnext;

    assert(s->no == FREESTATE);
    for (ab=s->oas.next ; ab!=NULL ; ab=abnext) {
	abnext = ab->next;
	FREE(ab);
	nfa->v->spaceused -= sizeof(struct arcbatch);
    }
    s->ins = NULL;
    s->outs = NULL;
    s->next = NULL;
    FREE(s);
    nfa->v->spaceused -= sizeof(struct state);
}
 
/*
 - newarc - set up a new arc within an NFA
 ^ static void newarc(struct nfa *, int, pcolor, struct state *,
 ^	struct state *);
 */
/*
 * This function checks to make sure that no duplicate arcs are created.
 * In general we never want duplicates.
 */
static void
newarc(
    struct nfa *nfa,
    int t,
    pcolor co,
    struct state *from,
    struct state *to)
{
    struct arc *a;

    assert(from != NULL && to != NULL);


    /* check for duplicate arc, using whichever chain is shorter */

    if (from->nouts <= to->nins) {
	for (a = from->outs; a != NULL; a = a->outchain) {
	    if (a->to == to && a->co == co && a->type == t) {
		return;
	    }

	}
    } else {
	for (a = to->ins; a != NULL; a = a->inchain) {
	    if (a->from == from && a->co == co && a->type == t) {
		return;
	    }
	}
    }
  
    /* no dup, so create the arc */
    createarc(nfa, t, co, from, to);
}

/*
 * createarc - create a new arc within an NFA
 *
 * This function must *only* be used after verifying that there is no existing
 * identical arc (same type/color/from/to).
 */
static void
createarc(
    struct nfa * nfa,
    int t,
    pcolor co,
    struct state * from,
    struct state * to)
{
    struct arc *a;

    /* the arc is physically allocated within its from-state */
    a = allocarc(nfa, from);
    if (NISERR()) {
	return;
    }
    assert(a != NULL);

    a->type = t;
    a->co = (color) co;
    a->to = to;
    a->from = from;

    /*
     * Put the new arc on the beginning, not the end, of the chains; it's
     * simpler here, and freearc() is the same cost either way.  See also the
     * logic in moveins() and its cohorts, as well as fixempties().

     */

    a->inchain = to->ins;
    a->inchainRev = NULL;
    if (to->ins) {
	to->ins->inchainRev = a;
    }
    to->ins = a;
    a->outchain = from->outs;
    a->outchainRev = NULL;
    if (from->outs) {
	from->outs->outchainRev = a;
    }
    from->outs = a;

    from->nouts++;
    to->nins++;

    if (COLORED(a) && nfa->parent == NULL) {
	colorchain(nfa->cm, a);
................................................................................
    }

    /*
     * if none at hand, get more
     */

    if (s->free == NULL) {
	struct arcbatch *newAb;

	int i;

	if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE) {
	    NERR(REG_ETOOBIG);
	    return NULL;
	}
	newAb = (struct arcbatch *) MALLOC(sizeof(struct arcbatch));
	if (newAb == NULL) {
	    NERR(REG_ESPACE);
	    return NULL;
	}
	nfa->v->spaceused += sizeof(struct arcbatch);
	newAb->next = s->oas.next;
	s->oas.next = newAb;

	for (i=0 ; i<ABSIZE ; i++) {
	    newAb->a[i].type = 0;
	    newAb->a[i].freechain = &newAb->a[i+1];
	}
................................................................................
static void
freearc(
    struct nfa *nfa,
    struct arc *victim)
{
    struct state *from = victim->from;
    struct state *to = victim->to;
    struct arc *predecessor;

    assert(victim->type != 0);

    /*
     * Take it off color chain if necessary.
     */

................................................................................
    }

    /*
     * Take it off source's out-chain.
     */

    assert(from != NULL);
    predecessor = victim->outchainRev;
    if (predecessor == NULL) {
	assert(from->outs == victim);

	from->outs = victim->outchain;
    } else {
	assert(predecessor->outchain == victim);
	predecessor->outchain = victim->outchain;
    }
    if (victim->outchain != NULL) {
	assert(victim->outchain->outchainRev == victim);
	victim->outchain->outchainRev = predecessor;
    }
    from->nouts--;

    /*
     * Take it off target's in-chain.
     */

    assert(to != NULL);
    predecessor = victim->inchainRev;
    if (predecessor == NULL) {
	assert(to->ins == victim);


	to->ins = victim->inchain;
    } else {
	assert(predecessor->inchain == victim);
	predecessor->inchain = victim->inchain;

    }
    if (victim->inchain != NULL) {
	assert(victim->inchain->inchainRev == victim);
	victim->inchain->inchainRev = predecessor;
    }
    to->nins--;

    /*
     * Clean up and place on from-state's free list.
     */

    victim->type = 0;
    victim->from = NULL;	/* precautions... */
    victim->to = NULL;
    victim->inchain = NULL;
    victim->inchainRev = NULL;
    victim->outchain = NULL;
    victim->outchainRev = NULL;
    victim->freechain = from->free;
    from->free = victim;
}

/*
 * changearctarget - flip an arc to have a different to state
 *
 * Caller must have verified that there is no pre-existing duplicate arc.
 *
 * Note that because we store arcs in their from state, we can't easily have
 * a similar changearcsource function.
 */
static void
changearctarget(struct arc * a, struct state * newto)
{
    struct state *oldto = a->to;
    struct arc *predecessor;

    assert(oldto != newto);

    /* take it off old target's in-chain */
    assert(oldto != NULL);
    predecessor = a->inchainRev;
    if (predecessor == NULL) {
	assert(oldto->ins == a);
	oldto->ins = a->inchain;
    } else {
	assert(predecessor->inchain == a);
	predecessor->inchain = a->inchain;
    }
    if (a->inchain != NULL) {
	assert(a->inchain->inchainRev == a);
	a->inchain->inchainRev = predecessor;
    }
    oldto->nins--;

    a->to = newto;

    /* prepend it to new target's in-chain */
    a->inchain = newto->ins;
    a->inchainRev = NULL;
    if (newto->ins) {
	newto->ins->inchainRev = a;
    }
    newto->ins = a;
    newto->nins++;
}
 
/*
 - hasnonemptyout - Does state have a non-EMPTY out arc?
 ^ static int hasnonemptyout(struct state *);
 */
static int
hasnonemptyout(
................................................................................
    for (a = s->outs; a != NULL; a = a->outchain) {
	if (a->type != EMPTY) {
	    return 1;
	}
    }
    return 0;
}






































 
/*
 - findarc - find arc, if any, from given source with given type and color
 * If there is more than one such arc, the result is random.
 ^ static struct arc *findarc(struct state *, int, pcolor);
 */
static struct arc *
................................................................................
    struct nfa *nfa,
    struct arc *oa,
    struct state *from,
    struct state *to)
{
    newarc(nfa, oa->type, oa->co, from, to);
}

/*
 * sortins - sort the in arcs of a state by from/color/type
 */
static void
sortins(
    struct nfa * nfa,
    struct state * s)
{
    struct arc **sortarray;
    struct arc *a;
    int n = s->nins;
    int i;

    if (n <= 1) {
	return;		/* nothing to do */
    }
    /* make an array of arc pointers ... */
    sortarray = (struct arc **) MALLOC(n * sizeof(struct arc *));
    if (sortarray == NULL) {
	NERR(REG_ESPACE);
	return;
    }
    i = 0;
    for (a = s->ins; a != NULL; a = a->inchain) {
	sortarray[i++] = a;
    }
    assert(i == n);
    /* ... sort the array */
    qsort(sortarray, n, sizeof(struct arc *), sortins_cmp);
    /* ... and rebuild arc list in order */
    /* it seems worth special-casing first and last items to simplify loop */
    a = sortarray[0];
    s->ins = a;
    a->inchain = sortarray[1];
    a->inchainRev = NULL;
    for (i = 1; i < n - 1; i++) {
	a = sortarray[i];
	a->inchain = sortarray[i + 1];
	a->inchainRev = sortarray[i - 1];
    }
    a = sortarray[i];
    a->inchain = NULL;
    a->inchainRev = sortarray[i - 1];
    FREE(sortarray);
}

static int
sortins_cmp(
    const void *a,
    const void *b)
{
    const struct arc *aa = *((const struct arc * const *) a);
    const struct arc *bb = *((const struct arc * const *) b);

    /* we check the fields in the order they are most likely to be different */
    if (aa->from->no < bb->from->no) {
	return -1;
    }
    if (aa->from->no > bb->from->no) {
 	return 1;
    }
    if (aa->co < bb->co) {
 	return -1;
    }
    if (aa->co > bb->co) {
 	return 1;
    }
    if (aa->type < bb->type) {
 	return -1;
    }
    if (aa->type > bb->type) {
 	return 1;
    }
    return 0;
}
 
/*
 * sortouts - sort the out arcs of a state by to/color/type
 */
static void
sortouts(
    struct nfa * nfa,
    struct state * s)
{
    struct arc **sortarray;
    struct arc *a;
    int	n = s->nouts;
    int	i;

    if (n <= 1) {
	return;					/* nothing to do */
    }
    /* make an array of arc pointers ... */
    sortarray = (struct arc **) MALLOC(n * sizeof(struct arc *));
    if (sortarray == NULL) {
	NERR(REG_ESPACE);
	return;
    }
    i = 0;
    for (a = s->outs; a != NULL; a = a->outchain) {
	sortarray[i++] = a;
    }
    assert(i == n);
    /* ... sort the array */
    qsort(sortarray, n, sizeof(struct arc *), sortouts_cmp);
    /* ... and rebuild arc list in order */
    /* it seems worth special-casing first and last items to simplify loop */
    a = sortarray[0];
    s->outs = a;
    a->outchain = sortarray[1];
    a->outchainRev = NULL;
    for (i = 1; i < n - 1; i++) {
	a = sortarray[i];
	a->outchain = sortarray[i + 1];
	a->outchainRev = sortarray[i - 1];
    }
    a = sortarray[i];
    a->outchain = NULL;
    a->outchainRev = sortarray[i - 1];
    FREE(sortarray);
}

static int
sortouts_cmp(
    const void *a,
    const void *b)
{
    const struct arc *aa = *((const struct arc * const *) a);
    const struct arc *bb = *((const struct arc * const *) b);

    /* we check the fields in the order they are most likely to be different */
    if (aa->to->no < bb->to->no) {
	return -1;
    }
    if (aa->to->no > bb->to->no) {
	return 1;
    }
    if (aa->co < bb->co) {
	return -1;
    }
    if (aa->co > bb->co) {
	return 1;
    }
    if (aa->type < bb->type) {
	return -1;
    }
    if (aa->type > bb->type) {
	return 1;
    }
    return 0;
}

/*
 * Common decision logic about whether to use arc-by-arc operations or
 * sort/merge.  If there's just a few source arcs we cannot recoup the
 * cost of sorting the destination arc list, no matter how large it is.
 * Otherwise, limit the number of arc-by-arc comparisons to about 1000
 * (a somewhat arbitrary choice, but the breakeven point would probably
 * be machine dependent anyway).
 */
#define BULK_ARC_OP_USE_SORT(nsrcarcs, ndestarcs) \
	((nsrcarcs) < 4 ? 0 : ((nsrcarcs) > 32 || (ndestarcs) > 32))
 
/*
 - moveins - move all in arcs of a state to another state
 * You might think this could be done better by just updating the
 * existing arcs, and you would be right if it weren't for the need
 * for duplicate suppression, which makes it easier to just make new
 * ones to exploit the suppression built into newarc.
 *
 * However, if we have a whole lot of arcs to deal with, retail duplicate
 * checks become too slow.  In that case we proceed by sorting and merging
 * the arc lists, and then we can indeed just update the arcs in-place.
 *
 ^ static void moveins(struct nfa *, struct state *, struct state *);
 */
static void
moveins(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState)
{
    assert(oldState != newState);

    if (!BULK_ARC_OP_USE_SORT(oldState->nins, newState->nins)) {
	/* With not too many arcs, just do them one at a time */
	struct arc *a;

	while ((a = oldState->ins) != NULL) {
	    cparc(nfa, a, a->from, newState);
	    freearc(nfa, a);
	}
    } else {
	/*
	 * With many arcs, use a sort-merge approach.  Note changearctarget()
	 * will put the arc onto the front of newState's chain, so it does not
	 * break our walk through the sorted part of the chain.
	 */
	struct arc *oa;
	struct arc *na;

	/*
	 * Because we bypass newarc() in this code path, we'd better include a
	 * cancel check.
	 */
	if (CANCEL_REQUESTED(nfa->v->re)) {
	    NERR(REG_CANCEL);
	    return;
	}

	sortins(nfa, oldState);
	sortins(nfa, newState);
	if (NISERR()) {
	    return;		/* might have failed to sort */
	}
	oa = oldState->ins;
	na = newState->ins;
	while (oa != NULL && na != NULL) {
	    struct arc *a = oa;

	    switch (sortins_cmp(&oa, &na)) {
		case -1:
		    /* newState does not have anything matching oa */
		    oa = oa->inchain;

		    /*
		     * Rather than doing createarc+freearc, we can just unlink
		     * and relink the existing arc struct.
		     */
		    changearctarget(a, newState);
		    break;
		case 0:
		    /* match, advance in both lists */
		    oa = oa->inchain;
		    na = na->inchain;
		    /* ... and drop duplicate arc from oldState */
		    freearc(nfa, a);
		    break;
		case +1:
		    /* advance only na; oa might have a match later */
		    na = na->inchain;
		    break;
		default:
		    assert(NOTREACHED);
	    }
	}
	while (oa != NULL) {
	    /* newState does not have anything matching oa */
	    struct arc *a = oa;

	    oa = oa->inchain;
	    changearctarget(a, newState);
	}
    }

    assert(oldState->nins == 0);
    assert(oldState->ins == NULL);
}
 
/*
 - copyins - copy in arcs of a state to another state

 ^ static VOID copyins(struct nfa *, struct state *, struct state *, int);
 */
static void
copyins(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState)

{
    assert(oldState != newState);

    if (!BULK_ARC_OP_USE_SORT(oldState->nins, newState->nins)) {
	/* With not too many arcs, just do them one at a time */
	struct arc *a;

	for (a = oldState->ins; a != NULL; a = a->inchain) {
	    cparc(nfa, a, a->from, newState);
	}
    } else {
	/*
	 * With many arcs, use a sort-merge approach.  Note that createarc()
	 * will put new arcs onto the front of newState's chain, so it does
	 * not break our walk through the sorted part of the chain.
	 */
	struct arc *oa;
	struct arc *na;

	/*
	 * Because we bypass newarc() in this code path, we'd better include a
	 * cancel check.
	 */
	if (CANCEL_REQUESTED(nfa->v->re)) {
	    NERR(REG_CANCEL);
	    return;
	}

	sortins(nfa, oldState);
	sortins(nfa, newState);
	if (NISERR()) {
	    return;		/* might have failed to sort */
	}
	oa = oldState->ins;


	na = newState->ins;
	while (oa != NULL && na != NULL) {
	    struct arc *a = oa;

	    switch (sortins_cmp(&oa, &na)) {
		case -1:
		    /* newState does not have anything matching oa */
		    oa = oa->inchain;
		    createarc(nfa, a->type, a->co, a->from, newState);
		    break;
		case 0:
		    /* match, advance in both lists */
		    oa = oa->inchain;
		    na = na->inchain;
		    break;
		case +1:
		    /* advance only na; oa might have a match later */
		    na = na->inchain;
		    break;
		default:
		    assert(NOTREACHED);
	    }
	}
	while (oa != NULL) {
	    /* newState does not have anything matching oa */
	    struct arc *a = oa;

	    oa = oa->inchain;
	    createarc(nfa, a->type, a->co, a->from, newState);
	}
    }
}

/*
 * mergeins - merge a list of inarcs into a state
 *
 * This is much like copyins, but the source arcs are listed in an array,
 * and are not guaranteed unique.  It's okay to clobber the array contents.
 */
static void
mergeins(
    struct nfa * nfa,
    struct state * s,
    struct arc ** arcarray,
    int arccount)
{
    struct arc *na;
    int	i;
    int	j;

    if (arccount <= 0) {
	return;
    }

    /*
     * Because we bypass newarc() in this code path, we'd better include a
     * cancel check.
     */
    if (CANCEL_REQUESTED(nfa->v->re)) {
	NERR(REG_CANCEL);
	return;
    }

    /* Sort existing inarcs as well as proposed new ones */
    sortins(nfa, s);
    if (NISERR()) {
	return;			/* might have failed to sort */
    }

    qsort(arcarray, arccount, sizeof(struct arc *), sortins_cmp);

    /*
     * arcarray very likely includes dups, so we must eliminate them.  (This
     * could be folded into the next loop, but it's not worth the trouble.)
     */
    j = 0;
    for (i = 1; i < arccount; i++) {
	switch (sortins_cmp(&arcarray[j], &arcarray[i])) {
	    case -1:
		/* non-dup */
		arcarray[++j] = arcarray[i];
		break;
	    case 0:
		/* dup */
		break;
	    default:
		/* trouble */
		assert(NOTREACHED);
	}
    }
    arccount = j + 1;

    /*
     * Now merge into s' inchain.  Note that createarc() will put new arcs
     * onto the front of s's chain, so it does not break our walk through the
     * sorted part of the chain.
     */
    i = 0;
    na = s->ins;
    while (i < arccount && na != NULL) {
	struct arc *a = arcarray[i];

	switch (sortins_cmp(&a, &na)) {
	    case -1:
		/* s does not have anything matching a */
		createarc(nfa, a->type, a->co, a->from, s);
		i++;
		break;
	    case 0:
		/* match, advance in both lists */
		i++;
		na = na->inchain;
		break;
	    case +1:
		/* advance only na; array might have a match later */
		na = na->inchain;
		break;
	    default:
		assert(NOTREACHED);
	}
    }
    while (i < arccount) {
	/* s does not have anything matching a */
	struct arc *a = arcarray[i];

	createarc(nfa, a->type, a->co, a->from, s);
	i++;
    }
}
 
/*
 - moveouts - move all out arcs of a state to another state
 ^ static void moveouts(struct nfa *, struct state *, struct state *);
 */
static void
moveouts(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState)
{
    assert(oldState != newState);

    if (!BULK_ARC_OP_USE_SORT(oldState->nouts, newState->nouts)) {
	/* With not too many arcs, just do them one at a time */
	struct arc *a;

	while ((a = oldState->outs) != NULL) {
	    cparc(nfa, a, newState, a->to);
	    freearc(nfa, a);
	}
    } else {
	/*
	 * With many arcs, use a sort-merge approach.  Note that createarc()
	 * will put new arcs onto the front of newState's chain, so it does
	 * not break our walk through the sorted part of the chain.
	 */
	struct arc *oa;
	struct arc *na;

	/*
	 * Because we bypass newarc() in this code path, we'd better include a
	 * cancel check.
	 */
	if (CANCEL_REQUESTED(nfa->v->re)) {
	    NERR(REG_CANCEL);
	    return;
	}

	sortouts(nfa, oldState);
	sortouts(nfa, newState);
	if (NISERR()) {
	    return;	/* might have failed to sort */
	}
	oa = oldState->outs;
	na = newState->outs;
	while (oa != NULL && na != NULL) {
	    struct arc *a = oa;

	    switch (sortouts_cmp(&oa, &na)) {
		case -1:
		    /* newState does not have anything matching oa */
		    oa = oa->outchain;
		    createarc(nfa, a->type, a->co, newState, a->to);
		    freearc(nfa, a);
		    break;
		case 0:
		    /* match, advance in both lists */
		    oa = oa->outchain;
		    na = na->outchain;
		    /* ... and drop duplicate arc from oldState */
		    freearc(nfa, a);
		    break;
		case +1:
		    /* advance only na; oa might have a match later */
		    na = na->outchain;
		    break;
		default:
		    assert(NOTREACHED);
	    }
	}
	while (oa != NULL) {
	    /* newState does not have anything matching oa */
	    struct arc *a = oa;

	    oa = oa->outchain;
	    createarc(nfa, a->type, a->co, newState, a->to);
	    freearc(nfa, a);
	}
    }

    assert(oldState->nouts == 0);
    assert(oldState->outs == NULL);
}
 
/*
 - copyouts - copy out arcs of a state to another state

 ^ static VOID copyouts(struct nfa *, struct state *, struct state *, int);
 */
static void
copyouts(
    struct nfa *nfa,
    struct state *oldState,
    struct state *newState)

{
    assert(oldState != newState);

    if (!BULK_ARC_OP_USE_SORT(oldState->nouts, newState->nouts)) {
	/* With not too many arcs, just do them one at a time */
	struct arc *a;

	for (a = oldState->outs; a != NULL; a = a->outchain) {
	    cparc(nfa, a, newState, a->to);
	}
    } else {
 	/*
	 * With many arcs, use a sort-merge approach.  Note that createarc()
	 * will put new arcs onto the front of newState's chain, so it does
	 * not break our walk through the sorted part of the chain.
	 */
	struct arc *oa;
	struct arc *na;

	/*
	 * Because we bypass newarc() in this code path, we'd better include a
	 * cancel check.
	 */
	if (CANCEL_REQUESTED(nfa->v->re)) {
	    NERR(REG_CANCEL);
	    return;
	}

	sortouts(nfa, oldState);
	sortouts(nfa, newState);
	if (NISERR()) {
	    return;		/* might have failed to sort */
	}
	oa = oldState->outs;

	na = newState->outs;
	while (oa != NULL && na != NULL) {
	    struct arc *a = oa;

	    switch (sortouts_cmp(&oa, &na)) {
		case -1:
		    /* newState does not have anything matching oa */
		    oa = oa->outchain;
		    createarc(nfa, a->type, a->co, newState, a->to);
		    break;
		case 0:
		    /* match, advance in both lists */
		    oa = oa->outchain;
		    na = na->outchain;
		    break;
		case +1:
		    /* advance only na; oa might have a match later */
		    na = na->outchain;
		    break;
		default:
		    assert(NOTREACHED);
	    }
	}
	while (oa != NULL) {
	    /* newState does not have anything matching oa */
	    struct arc *a = oa;

	    oa = oa->outchain;
	    createarc(nfa, a->type, a->co, newState, a->to);
	}
    }
}
 
/*
 - cloneouts - copy out arcs of a state to another state pair, modifying type
 ^ static void cloneouts(struct nfa *, struct state *, struct state *,
 ^ 	struct state *, int);
................................................................................
    }
}
 
/*
 - optimize - optimize an NFA
 ^ static long optimize(struct nfa *, FILE *);
 */

 /*
  * The main goal of this function is not so much "optimization" (though it
  * does try to get rid of useless NFA states) as reducing the NFA to a form
  * the regex executor can handle.  The executor, and indeed the cNFA format
  * that is its input, can only handle PLAIN and LACON arcs.  The output of
  * the regex parser also includes EMPTY (do-nothing) arcs, as well as
  * ^, $, AHEAD, and BEHIND constraint arcs, which we must get rid of here.
  * We first get rid of EMPTY arcs and then deal with the constraint arcs.
  * The hardest part of either job is to get rid of circular loops of the
  * target arc type.  We would have to do that in any case, though, as such a
  * loop would otherwise allow the executor to cycle through the loop endlessly
  * without making any progress in the input string.
  */
static long			/* re_info bits */
optimize(
    struct nfa *nfa,
    FILE *f)			/* for debug output; NULL none */
{
    int verbose = (f != NULL) ? 1 : 0;

................................................................................
    if (verbose) {
	fprintf(f, "\nempties:\n");
    }
    fixempties(nfa, f);		/* get rid of EMPTY arcs */
    if (verbose) {
	fprintf(f, "\nconstraints:\n");
    }
    fixconstraintloops(nfa, f);	/* get rid of constraint loops */
    pullback(nfa, f);		/* pull back constraints backward */
    pushfwd(nfa, f);		/* push fwd constraints forward */
    if (verbose) {
	fprintf(f, "\nfinal cleanup:\n");
    }
    cleanup(nfa);		/* final tidying */
#ifdef REG_DEBUG
    if (verbose) {
	dumpnfa(nfa, f);
    }
#endif
    return analyze(nfa);	/* and analysis */
}
 
/*
 - pullback - pull back constraints backward to eliminate them
 ^ static void pullback(struct nfa *, FILE *);
 */
static void
pullback(
    struct nfa *nfa,
    FILE *f)			/* for debug output; NULL none */
{
    struct state *s;
    struct state *nexts;
    struct arc *a;
    struct arc *nexta;
    struct state *intermediates;
    int progress;

    /*
     * Find and pull until there are no more.
     */

    do {
	progress = 0;
	for (s=nfa->states ; s!=NULL && !NISERR() ; s=nexts) {
	    nexts = s->next;
	    intermediates = NULL;
	    for (a=s->outs ; a!=NULL && !NISERR() ; a=nexta) {
		nexta = a->outchain;
		if (a->type == '^' || a->type == BEHIND) {
		    if (pull(nfa, a, &intermediates)) {
			progress = 1;
		    }
		}
		assert(nexta == NULL || s->no != FREESTATE);
	    }
	    /* clear tmp fields of intermediate states created here */
	    while (intermediates != NULL) {
		struct state *ns = intermediates->tmp;

		intermediates->tmp = NULL;
		intermediates = ns;
	    }
	    /* if s is now useless, get rid of it */
	    if ((s->nins == 0 || s->nouts == 0) && !s->flag) {
		dropstate(nfa, s);
	    }
	}
	if (progress && f != NULL) {
	    dumpnfa(nfa, f);
	}
    } while (progress && !NISERR());
    if (NISERR()) {
	return;
    }

    /*
     * Any ^ constraints we were able to pull to the start state can now be
     * replaced by PLAIN arcs referencing the BOS or BOL colors.  There should
     * be no other ^ or BEHIND arcs left in the NFA, though we do not check
     * that here (compact() will fail if so).
     */
    for (a=nfa->pre->outs ; a!=NULL ; a=nexta) {
	nexta = a->outchain;
	if (a->type == '^') {
	    assert(a->co == 0 || a->co == 1);
	    newarc(nfa, PLAIN, nfa->bos[a->co], a->from, a->to);
	    freearc(nfa, a);
	}
    }
}
 
/*
 - pull - pull a back constraint backward past its source state
 *
 * Returns 1 if successful (which it always is unless the source is the
 * start state or we have an internal error), 0 if nothing happened.
 *
 * A significant property of this function is that it deletes no pre-existing
 * states, and no outarcs of the constraint's from state other than the given

 * constraint arc.  This makes the loops in pullback() safe, at the cost that
 * we may leave useless states behind.  Therefore, we leave it to pullback()
 * to delete such states.
 *
 * If the from state has multiple back-constraint outarcs, and/or multiple
 * compatible constraint inarcs, we only need to create one new intermediate
 * state per combination of predecessor and successor states.  *intermediates
 * points to a list of such intermediate states for this from state (chained
 * through their tmp fields).
 ^ static int pull(struct nfa *, struct arc *);
 */
static int
pull(
    struct nfa *nfa,
    struct arc *con,
    struct state **intermediates)
{
    struct state *from = con->from;
    struct state *to = con->to;
    struct arc *a;
    struct arc *nexta;
    struct state *s;

    assert(from != to);		/* should have gotten rid of this earlier */



    if (from->flag) {		/* can't pull back beyond start */
	return 0;
    }
    if (from->nins == 0) {	/* unreachable */
	freearc(nfa, con);
	return 1;
    }

    /*



















     * First, clone from state if necessary to avoid other outarcs.  This may
     * seem wasteful, but it simplifies the logic, and we'll get rid of the
     * clone state again at the bottom.
     */

    if (from->nouts > 1) {
	s = newstate(nfa);
	if (NISERR()) {
	    return 0;
	}

	copyins(nfa, from, s);	/* duplicate inarcs */
	cparc(nfa, con, s, to);		/* move constraint arc */
	freearc(nfa, con);
	if (NISERR()) {
	    return 0;
	}
	from = s;
	con = from->outs;
    }
    assert(from->nouts == 1);

    /*
     * Propagate the constraint into the from state's inarcs.
     */

    for (a=from->ins ; a!=NULL && !NISERR(); a=nexta) {
	nexta = a->inchain;
	switch (combine(con, a)) {
	case INCOMPATIBLE:	/* destroy the arc */
	    freearc(nfa, a);
	    break;
	case SATISFIED:		/* no action needed */
	    break;
	case COMPATIBLE:	/* swap the two arcs, more or less */
	    /* need an intermediate state, but might have one already */
	    for (s = *intermediates; s != NULL; s = s->tmp) {
		assert(s->nins > 0 && s->nouts > 0);
		if (s->ins->from == a->from && s->outs->to == to) {
		    break;
		}
	    }
	    if (s == NULL) {
		s = newstate(nfa);
		if (NISERR()) {
		    return 0;
		}




		s->tmp = *intermediates;
		*intermediates = s;
	    }
  	    cparc(nfa, con, a->from, s);
	    cparc(nfa, a, s, to);
 	    freearc(nfa, a);
  	    break;
	default:
	    assert(NOTREACHED);
	    break;
	}
    }

    /*
     * Remaining inarcs, if any, incorporate the constraint.
     */

    moveins(nfa, from, to);
    freearc(nfa, con);
    /* from state is now useless, but we leave it to pullback() to clean up */
    return 1;
}
 
/*
 - pushfwd - push forward constraints forward to eliminate them
 ^ static void pushfwd(struct nfa *, FILE *);
 */
static void
pushfwd(
    struct nfa *nfa,
    FILE *f)			/* for debug output; NULL none */
{
    struct state *s;
    struct state *nexts;
    struct arc *a;
    struct arc *nexta;
    struct state *intermediates;
    int progress;

    /*
     * Find and push until there are no more.
     */

    do {
	progress = 0;
	for (s=nfa->states ; s!=NULL && !NISERR() ; s=nexts) {
	    nexts = s->next;
	    intermediates = NULL;
	    for (a = s->ins; a != NULL && !NISERR(); a = nexta) {
		nexta = a->inchain;
		if (a->type == '$' || a->type == AHEAD) {
		    if (push(nfa, a, &intermediates)) {
			progress = 1;
		    }
		}

	    }
	    /* clear tmp fields of intermediate states created here */
	    while (intermediates != NULL) {
		struct state *ns = intermediates->tmp;

		intermediates->tmp = NULL;
		intermediates = ns;
	    }
	    /* if s is now useless, get rid of it */
	    if ((s->nins == 0 || s->nouts == 0) && !s->flag) {
		dropstate(nfa, s);
	    }
	}
	if (progress && f != NULL) {
	    dumpnfa(nfa, f);
	}
    } while (progress && !NISERR());
    if (NISERR()) {
	return;
    }

    /*
     * Any $ constraints we were able to push to the post state can now be
     * replaced by PLAIN arcs referencing the EOS or EOL colors.  There should
     * be no other $ or AHEAD arcs left in the NFA, though we do not check
     * that here (compact() will fail if so).
     */
    for (a = nfa->post->ins; a != NULL; a = nexta) {
	nexta = a->inchain;
	if (a->type == '$') {
	    assert(a->co == 0 || a->co == 1);
	    newarc(nfa, PLAIN, nfa->eos[a->co], a->from, a->to);
	    freearc(nfa, a);
	}
    }
}
 
/*
 - push - push a forward constraint forward past its destination state
 *
 * Returns 1 if successful (which it always is unless the destination is the
 * post state or we have an internal error), 0 if nothing happened.
 *
 * A significant property of this function is that it deletes no pre-existing


 * states, and no inarcs of the constraint's to state other than the given
 * constraint arc.  This makes the loops in pushfwd() safe, at the cost that
 * we may leave useless states behind.  Therefore, we leave it to pushfwd()
 * to delete such states.
 *
 * If the to state has multiple forward-constraint inarcs, and/or multiple
 * compatible constraint outarcs, we only need to create one new intermediate
 * state per combination of predecessor and successor states.  *intermediates
 * points to a list of such intermediate states for this to state (chained
 * through their tmp fields).
 ^ static int push(struct nfa *, struct arc *);
 */
static int
push(
    struct nfa *nfa,
    struct arc *con,
    struct state **intermediates)
{
    struct state *from = con->from;
    struct state *to = con->to;
    struct arc *a;
    struct arc *nexta;
    struct state *s;

    assert(to != from);		/* should have gotten rid of this earlier */



    if (to->flag) {		/* can't push forward beyond end */
	return 0;
    }
    if (to->nouts == 0) {	/* dead end */
	freearc(nfa, con);
	return 1;
    }

    /*






















     * First, clone to state if necessary to avoid other inarcs.  This may
     * seem wasteful, but it simplifies the logic, and we'll get rid of the
     * clone state again at the bottom.
     */

    if (to->nins > 1) {
	s = newstate(nfa);
	if (NISERR()) {
	    return 0;
	}
	copyouts(nfa, to, s);		/* duplicate outarcs */
	cparc(nfa, con, from, s);	/* move constraint arc */
	freearc(nfa, con);
	if (NISERR()) {
	    return 0;
	}
	to = s;
	con = to->ins;
    }
    assert(to->nins == 1);

    /*
     * Propagate the constraint into the to state's outarcs.
     */

    for (a = to->outs; a != NULL && !NISERR(); a = nexta) {
	nexta = a->outchain;
	switch (combine(con, a)) {
	case INCOMPATIBLE:	/* destroy the arc */
	    freearc(nfa, a);
	    break;
	case SATISFIED:		/* no action needed */
	    break;
	case COMPATIBLE:	/* swap the two arcs, more or less */
	    /* need an intermediate state, but might have one already */
	    for (s = *intermediates; s != NULL; s = s->tmp) {
		assert(s->nins > 0 && s->nouts > 0);
		if (s->ins->from == from && s->outs->to == a->to) {
		    break;
		}
	    }
	    if (s == NULL) {
		s = newstate(nfa);
		if (NISERR()) {
		    return 0;
		}
		s->tmp = *intermediates;
		*intermediates = s;
	    }
	    cparc(nfa, con, s, a->to);
  	    cparc(nfa, a, from, s);



  	    freearc(nfa, a);
  	    break;
	default:
	    assert(NOTREACHED);
	    break;
	}
    }

    /*
     * Remaining outarcs, if any, incorporate the constraint.
     */

    moveouts(nfa, to, from);
    freearc(nfa, con);
    /* to state is now useless, but we leave it to pushfwd() to clean up */
    return 1;
}
 
/*
 - combine - constraint lands on an arc, what happens?
 ^ #def	INCOMPATIBLE	1	// destroys arc
 ^ #def	SATISFIED	2	// constraint satisfied
................................................................................
    FILE *f)			/* for debug output; NULL none */
{
    struct state *s;
    struct state *s2;
    struct state *nexts;
    struct arc *a;
    struct arc *nexta;
    int totalinarcs;
    struct arc **inarcsorig;
    struct arc **arcarray;
    int arccount;
    int prevnins;
    int nskip;

    /*
     * First, get rid of any states whose sole out-arc is an EMPTY,
     * since they're basically just aliases for their successor.  The
     * parsing algorithm creates enough of these that it's worth
     * special-casing this.
     */
................................................................................
	    continue;
	}
	if (s != a->from) {
	    moveouts(nfa, s, a->from);
	}
	dropstate(nfa, s);
    }

    if (NISERR()) {
	return;
    }

    /*
     * For each remaining NFA state, find all other states from which it is
     * reachable by a chain of one or more EMPTY arcs.  Then generate new arcs
     * that eliminate the need for each such chain.
     *




     * We could replace a chain of EMPTY arcs that leads from a "from" state
     * to a "to" state either by pushing non-EMPTY arcs forward (linking
     * directly from "from"'s predecessors to "to") or by pulling them back
     * (linking directly from "from" to "to"'s successors).  We choose to
     * always do the former; this choice is somewhat arbitrary, but the
     * approach below requires that we uniformly do one or the other.

     *
     * Suppose we have a chain of N successive EMPTY arcs (where N can easily
     * approach the size of the NFA).  All of the intermediate states must
     * have additional inarcs and outarcs, else they'd have been removed by
     * the steps above.  Assuming their inarcs are mostly not empties, we will
     * add O(N^2) arcs to the NFA, since a non-EMPTY inarc leading to any one
     * state in the chain must be duplicated to lead to all its successor
     * states as well.  So there is no hope of doing less than O(N^2) work;
     * however, we should endeavor to keep the big-O cost from being even
     * worse than that, which it can easily become without care.  In
     * particular, suppose we were to copy all S1's inarcs forward to S2, and
     * then also to S3, and then later we consider pushing S2's inarcs forward
     * to S3.  If we include the arcs already copied from S1 in that, we'd be
     * doing O(N^3) work.  (The duplicate-arc elimination built into newarc()
     * and its cohorts would get rid of the extra arcs, but not without cost.)
     *
     * We can avoid this cost by treating only arcs that existed at the start
     * of this phase as candidates to be pushed forward.  To identify those,
     * we remember the first inarc each state had to start with.  We rely on
     * the fact that newarc() and friends put new arcs on the front of their
     * to-states' inchains, and that this phase never deletes arcs, so that
     * the original arcs must be the last arcs in their to-states' inchains.
     *
     * So the process here is that, for each state in the NFA, we gather up
     * all non-EMPTY inarcs of states that can reach the target state via
     * EMPTY arcs.  We then sort, de-duplicate, and merge these arcs into the
     * target state's inchain.  (We can safely use sort-merge for this as long
     * as we update each state's original-arcs pointer after we add arcs to
     * it; the sort step of mergeins probably changed the order of the old
     * arcs.)
     *
     * Another refinement worth making is that, because we only add non-EMPTY
     * arcs during this phase, and all added arcs have the same from-state as
     * the non-EMPTY arc they were cloned from, we know ahead of time that any
     * states having only EMPTY outarcs will be useless for lack of outarcs
     * after we drop the EMPTY arcs.  (They cannot gain non-EMPTY outarcs if
     * they had none to start with.)  So we need not bother to update the
     * inchains of such states at all.
     */

    /* Remember the states' first original inarcs */
    /* ... and while at it, count how many old inarcs there are altogether */
    inarcsorig = (struct arc **) MALLOC(nfa->nstates * sizeof(struct arc *));
    if (inarcsorig == NULL) {
	NERR(REG_ESPACE);
	return;
    }
    totalinarcs = 0;
    for (s = nfa->states; s != NULL; s = s->next) {


	inarcsorig[s->no] = s->ins;
	totalinarcs += s->nins;
    }

    /*




     * Create a workspace for accumulating the inarcs to be added to the
     * current target state.  totalinarcs is probably a considerable
     * overestimate of the space needed, but the NFA is unlikely to be large
     * enough at this point to make it worth being smarter.
     */
    arcarray = (struct arc **) MALLOC(totalinarcs * sizeof(struct arc *));
    if (arcarray == NULL) {
	NERR(REG_ESPACE);
	FREE(inarcsorig);
	return;
    }

    /* And iterate over the target states */
    for (s = nfa->states; s != NULL && !NISERR(); s = s->next) {
	/* Ignore target states without non-EMPTY outarcs, per note above */
	if (!s->flag && !hasnonemptyout(s)) {

	    continue;
	}

	/* Find predecessor states and accumulate their original inarcs */
	arccount = 0;
	for (s2 = emptyreachable(nfa, s, s, inarcsorig); s2 != s; s2 = nexts) {
	    /* Add s2's original inarcs to arcarray[], but ignore empties */
	    for (a = inarcsorig[s2->no]; a != NULL; a = a->inchain) {
		if (a->type != EMPTY) {
		    arcarray[arccount++] = a;
		}
	    }
  
  	    /* Reset the tmp fields as we walk back */
  	    nexts = s2->tmp;
  	    s2->tmp = NULL;
  	}
  	s->tmp = NULL;
	assert(arccount <= totalinarcs);

	/* Remember how many original inarcs this state has */
	prevnins = s->nins;

	/* Add non-duplicate inarcs to target state */
	mergeins(nfa, s, arcarray, arccount);

	/* Now we must update the state's inarcsorig pointer */
	nskip = s->nins - prevnins;
	a = s->ins;
	while (nskip-- > 0) {
	    a = a->inchain;
	}
	inarcsorig[s->no] = a;
    }
  
    FREE(arcarray);
    FREE(inarcsorig);

    if (NISERR()) {
	return;
    }

    /*
     * Remove all the EMPTY arcs, since we don't need them anymore.
     */
................................................................................

    if (f != NULL) {
	dumpnfa(nfa, f);
    }
}
 
/*
 - emptyreachable - recursively find all states that can reach s by EMPTY arcs
 * The return value is the last such state found.  Its tmp field links back
 * to the next-to-last such state, and so on back to s, so that all these
 * states can be located without searching the whole NFA.
 *
 * Since this is only used in fixempties(), we pass in the inarcsorig[] array
 * maintained by that function.  This lets us skip over all new inarcs, which
 * are certainly not EMPTY arcs.
 *
 * The maximum recursion depth here is equal to the length of the longest
 * loop-free chain of EMPTY arcs, which is surely no more than the size of
 * the NFA, and in practice will be less than that.
 ^ static struct state *emptyreachable(struct state *, struct state *);
 */
static struct state *
emptyreachable(
    struct nfa *nfa,
    struct state *s,
    struct state *lastfound,
    struct arc **inarcsorig)
{
    struct arc *a;

    s->tmp = lastfound;
    lastfound = s;
    for (a = inarcsorig[s->no]; a != NULL; a = a->inchain) {
	if (a->type == EMPTY && a->from->tmp == NULL) {
	    lastfound = emptyreachable(nfa, a->from, lastfound, inarcsorig);
	}
    }
    return lastfound;
}

/*
 * isconstraintarc - detect whether an arc is of a constraint type
 */
static inline int
isconstraintarc(struct arc * a)
{
    switch (a->type)
    {
	case '^':
	case '$':
	case BEHIND:
	case AHEAD:
	case LACON:
	    return 1;
    }
    return 0;
}

/*
 * hasconstraintout - does state have a constraint out arc?
 */
static int
hasconstraintout(struct state * s)
{
    struct arc *a;

    for (a = s->outs; a != NULL; a = a->outchain) {
	if (isconstraintarc(a)) {
	    return 1;
	}
    }
    return 0;
}

/*
 * fixconstraintloops - get rid of loops containing only constraint arcs
 *
 * A loop of states that contains only constraint arcs is useless, since
 * passing around the loop represents no forward progress.  Moreover, it
 * would cause infinite looping in pullback/pushfwd, so we need to get rid
 * of such loops before doing that.
 */
static void

fixconstraintloops(
    struct nfa * nfa,
    FILE *f)		/* for debug output; NULL none */
{
    struct state *s;
    struct state *nexts;
    struct arc *a;
    struct arc *nexta;
    int hasconstraints;



    /*
     * In the trivial case of a state that loops to itself, we can just drop
     * the constraint arc altogether.  This is worth special-casing because
     * such loops are far more common than loops containing multiple states.
     * While we're at it, note whether any constraint arcs survive.
     */
    hasconstraints = 0;
    for (s = nfa->states; s != NULL && !NISERR(); s = nexts) {
	nexts = s->next;
	/* while we're at it, ensure tmp fields are clear for next step */
	assert(s->tmp == NULL);
	for (a = s->outs; a != NULL && !NISERR(); a = nexta) {
	    nexta = a->outchain;
	    if (isconstraintarc(a)) {
		if (a->to == s) {
		    freearc(nfa, a);
		} else {
		    hasconstraints = 1;
 		}
	    }
	}
 	/* If we removed all the outarcs, the state is useless. */
 	if (s->nouts == 0 && !s->flag) {
 	    dropstate(nfa, s);
	}
    }
 
    /* Nothing to do if no remaining constraint arcs */
    if (NISERR() || !hasconstraints) {
	return;
    }

    /*
     * Starting from each remaining NFA state, search outwards for a
     * constraint loop.  If we find a loop, break the loop, then start the
     * search over.  (We could possibly retain some state from the first scan,
     * but it would complicate things greatly, and multi-state constraint
     * loops are rare enough that it's not worth optimizing the case.)
     */
  restart:
    for (s = nfa->states; s != NULL && !NISERR(); s = s->next) {
	if (findconstraintloop(nfa, s)) {
	    goto restart;
	}
    }

    if (NISERR()) {
	return;
    }

    /*
     * Now remove any states that have become useless.  (This cleanup is not
     * very thorough, and would be even less so if we tried to combine it with
     * the previous step; but cleanup() will take care of anything we miss.)
     *
     * Because findconstraintloop intentionally doesn't reset all tmp fields,
     * we have to clear them after it's done.  This is a convenient place to
     * do that, too.
     */
    for (s = nfa->states; s != NULL; s = nexts) {
	nexts = s->next;
	s->tmp = NULL;
	if ((s->nins == 0 || s->nouts == 0) && !s->flag) {
	    dropstate(nfa, s);
	}
    }

    if (f != NULL) {
 	dumpnfa(nfa, f);
    }
}

/*
 * findconstraintloop - recursively find a loop of constraint arcs
 *
 * If we find a loop, break it by calling breakconstraintloop(), then
 * return 1; otherwise return 0.
 *
 * State tmp fields are guaranteed all NULL on a success return, because
 * breakconstraintloop does that.  After a failure return, any state that
 * is known not to be part of a loop is marked with s->tmp == s; this allows
 * us not to have to re-prove that fact on later calls.  (This convention is
 * workable because we already eliminated single-state loops.)
 *
 * Note that the found loop doesn't necessarily include the first state we
 * are called on.  Any loop reachable from that state will do.
 *
 * The maximum recursion depth here is one more than the length of the longest
 * loop-free chain of constraint arcs, which is surely no more than the size
 * of the NFA, and in practice will be a lot less than that.
 */
static int
findconstraintloop(struct nfa * nfa, struct state * s)
{
    struct arc *a;

    /* Since this is recursive, it could be driven to stack overflow */
    if (STACK_TOO_DEEP(nfa->v->re)) {
	NERR(REG_ETOOBIG);
	return 1;		/* to exit as quickly as possible */
    }

    if (s->tmp != NULL) {
	/* Already proven uninteresting? */
	if (s->tmp == s) {
	    return 0;
	}
	/* Found a loop involving s */
	breakconstraintloop(nfa, s);
	/* The tmp fields have been cleaned up by breakconstraintloop */
	return 1;
    }
    for (a = s->outs; a != NULL; a = a->outchain) {
	if (isconstraintarc(a)) {
	    struct state *sto = a->to;

	    assert(sto != s);
	    s->tmp = sto;
	    if (findconstraintloop(nfa, sto)) {
		return 1;
	    }
	}
    }

    /*









     * If we get here, no constraint loop exists leading out from s.  Mark it
     * with s->tmp == s so we need not rediscover that fact again later.
     */



    s->tmp = s;
    return 0;
}

/*
 * breakconstraintloop - break a loop of constraint arcs
 *
 * sinitial is any one member state of the loop.  Each loop member's tmp
 * field links to its successor within the loop.  (Note that this function
 * will reset all the tmp fields to NULL.)
 *
 * We can break the loop by, for any one state S1 in the loop, cloning its
 * loop successor state S2 (and possibly following states), and then moving
 * all S1->S2 constraint arcs to point to the cloned S2.  The cloned S2 should
 * copy any non-constraint outarcs of S2.  Constraint outarcs should be
 * dropped if they point back to S1, else they need to be copied as arcs to
 * similarly cloned states S3, S4, etc.  In general, each cloned state copies
 * non-constraint outarcs, drops constraint outarcs that would lead to itself
 * or any earlier cloned state, and sends other constraint outarcs to newly
 * cloned states.  No cloned state will have any inarcs that aren't constraint
 * arcs or do not lead from S1 or earlier-cloned states.  It's okay to drop
 * constraint back-arcs since they would not take us to any state we've not
 * already been in; therefore, no new constraint loop is created.  In this way
 * we generate a modified NFA that can still represent every useful state
 * sequence, but not sequences that represent state loops with no consumption
 * of input data.  Note that the set of cloned states will certainly include
 * all of the loop member states other than S1, and it may also include
 * non-loop states that are reachable from S2 via constraint arcs.  This is
 * important because there is no guarantee that findconstraintloop found a
 * maximal loop (and searching for one would be NP-hard, so don't try).
 * Frequently the "non-loop states" are actually part of a larger loop that
 * we didn't notice, and indeed there may be several overlapping loops.
 * This technique ensures convergence in such cases, while considering only
 * the originally-found loop does not.
 *
 * If there is only one S1->S2 constraint arc, then that constraint is
 * certainly satisfied when we enter any of the clone states.  This means that
 * in the common case where many of the constraint arcs are identically
 * labeled, we can merge together clone states linked by a similarly-labeled
 * constraint: if we can get to the first one we can certainly get to the
 * second, so there's no need to distinguish.  This greatly reduces the number
 * of new states needed, so we preferentially break the given loop at a state
 * pair where this is true.
 *
 * Furthermore, it's fairly common to find that a cloned successor state has
 * no outarcs, especially if we're a bit aggressive about removing unnecessary
 * outarcs.  If that happens, then there is simply not any interesting state
 * that can be reached through the predecessor's loop arcs, which means we can
 * break the loop just by removing those loop arcs, with no new states added.
 */


static void
breakconstraintloop(struct nfa * nfa, struct state * sinitial)
{


    struct state *s;
    struct state *shead;
    struct state *stail;
    struct state *sclone;
    struct state *nexts;
    struct arc *refarc;
    struct arc *a;
    struct arc *nexta;

    /*
     * Start by identifying which loop step we want to break at.
     * Preferentially this is one with only one constraint arc.  (XXX are
     * there any other secondary heuristics we want to use here?)  Set refarc
     * to point to the selected lone constraint arc, if there is one.
     */
    refarc = NULL;
    s = sinitial;
    do {
	nexts = s->tmp;
	assert(nexts != s);	/* should not see any one-element loops */
	if (refarc == NULL) {
	    int narcs = 0;

	    for (a = s->outs; a != NULL; a = a->outchain) {
		if (a->to == nexts && isconstraintarc(a)) {
		    refarc = a;
		    narcs++;
		}
	    }
	    assert(narcs > 0);
	    if (narcs > 1) {
		refarc = NULL;	/* multiple constraint arcs here, no good */
	    }
	}
	s = nexts;
    } while (s != sinitial);

    if (refarc) {
	/* break at the refarc */
	shead = refarc->from;
	stail = refarc->to;
	assert(stail == shead->tmp);
    } else {
	/* for lack of a better idea, break after sinitial */
	shead = sinitial;
	stail = sinitial->tmp;
    }

    /*
     * Reset the tmp fields so that we can use them for local storage in
     * clonesuccessorstates.  (findconstraintloop won't mind, since it's just
     * going to abandon its search anyway.)
     */
    for (s = nfa->states; s != NULL; s = s->next) {
	s->tmp = NULL;
    }

    /*
     * Recursively build clone state(s) as needed.
     */
    sclone = newstate(nfa);
    if (sclone == NULL) {
	assert(NISERR());
	return;
    }



    clonesuccessorstates(nfa, stail, sclone, shead, refarc,
	    NULL, NULL, nfa->nstates);

    if (NISERR()) {
	return;
    }

    /*

     * It's possible that sclone has no outarcs at all, in which case it's
     * useless.  (We don't try extremely hard to get rid of useless states
     * here, but this is an easy and fairly common case.)
     */



    if (sclone->nouts == 0) {
	freestate(nfa, sclone);
	sclone = NULL;
    }

    /*
     * Move shead's constraint-loop arcs to point to sclone, or just drop them
     * if we discovered we don't need sclone.
     */


    for (a = shead->outs; a != NULL; a = nexta) {
	nexta = a->outchain;
	if (a->to == stail && isconstraintarc(a)) {
	    if (sclone) {
		cparc(nfa, a, shead, sclone);
	    }
	    freearc(nfa, a);
	    if (NISERR()) {
		break;
	    }
	}
    }
}

/*
 * clonesuccessorstates - create a tree of constraint-arc successor states
 *
 * ssource is the state to be cloned, and sclone is the state to copy its
 * outarcs into.  sclone's inarcs, if any, should already be set up.
 *
 * spredecessor is the original predecessor state that we are trying to build
 * successors for (it may not be the immediate predecessor of ssource).
 * refarc, if not NULL, is the original constraint arc that is known to have
 * been traversed out of spredecessor to reach the successor(s).
 *
 * For each cloned successor state, we transiently create a "donemap" that is
 * a boolean array showing which source states we've already visited for this
 * clone state.  This prevents infinite recursion as well as useless repeat
 * visits to the same state subtree (which can add up fast, since typical NFAs
 * have multiple redundant arc pathways).  Each donemap is a char array
 * indexed by state number.  The donemaps are all of the same size "nstates",
 * which is nfa->nstates as of the start of the recursion.  This is enough to
 * have entries for all pre-existing states, but *not* entries for clone
 * states created during the recursion.  That's okay since we have no need to
 * mark those.
 *
 * curdonemap is NULL when recursing to a new sclone state, or sclone's
 * donemap when we are recursing without having created a new state (which we
 * do when we decide we can merge a successor state into the current clone
 * state).  outerdonemap is NULL at the top level and otherwise the parent
 * clone state's donemap.
 *
 * The successor states we create and fill here form a strict tree structure,
 * with each state having exactly one predecessor, except that the toplevel
 * state has no inarcs as yet (breakconstraintloop will add its inarcs from
 * spredecessor after we're done).  Thus, we can examine sclone's inarcs back
 * to the root, plus refarc if any, to identify the set of constraints already
 * known valid at the current point.  This allows us to avoid generating extra
 * successor states.
 */
static void
clonesuccessorstates(
    struct nfa * nfa,
    struct state * ssource,
    struct state * sclone,
    struct state * spredecessor,
    struct arc * refarc,
    char *curdonemap,
    char *outerdonemap,
    int nstates)
{
    char *donemap;
    struct arc *a;

    /* Since this is recursive, it could be driven to stack overflow */
    if (STACK_TOO_DEEP(nfa->v->re)) {
	NERR(REG_ETOOBIG);
	return;
    }


    /* If this state hasn't already got a donemap, create one */
    donemap = curdonemap;
    if (donemap == NULL) {
	donemap = (char *) MALLOC(nstates * sizeof(char));
	if (donemap == NULL) {
	    NERR(REG_ESPACE);
	    return;
	}

	if (outerdonemap != NULL) {
	    /*
	     * Not at outermost recursion level, so copy the outer level's
	     * donemap; this ensures that we see states in process of being
	     * visited at outer levels, or already merged into predecessor
	     * states, as ones we shouldn't traverse back to.
	     */
	    memcpy(donemap, outerdonemap, nstates * sizeof(char));
	} else {
	    /* At outermost level, only spredecessor is off-limits */
	    memset(donemap, 0, nstates * sizeof(char));
	    assert(spredecessor->no < nstates);
	    donemap[spredecessor->no] = 1;
	}
    }

    /* Mark ssource as visited in the donemap */
    assert(ssource->no < nstates);
    assert(donemap[ssource->no] == 0);
    donemap[ssource->no] = 1;

    /*
     * We proceed by first cloning all of ssource's outarcs, creating new
     * clone states as needed but not doing more with them than that.  Then in
     * a second pass, recurse to process the child clone states.  This allows
     * us to have only one child clone state per reachable source state, even
     * when there are multiple outarcs leading to the same state.  Also, when
     * we do visit a child state, its set of inarcs is known exactly, which
     * makes it safe to apply the constraint-is-already-checked optimization.
     * Also, this ensures that we've merged all the states we can into the
     * current clone before we recurse to any children, thus possibly saving
     * them from making extra images of those states.
     *
     * While this function runs, child clone states of the current state are
     * marked by setting their tmp fields to point to the original state they
     * were cloned from.  This makes it possible to detect multiple outarcs
     * leading to the same state, and also makes it easy to distinguish clone
     * states from original states (which will have tmp == NULL).
     */
    for (a = ssource->outs; a != NULL && !NISERR(); a = a->outchain) {
	struct state *sto = a->to;

	/*
	 * We do not consider cloning successor states that have no constraint
	 * outarcs; just link to them as-is.  They cannot be part of a
	 * constraint loop so there is no need to make copies.  In particular,
	 * this rule keeps us from trying to clone the post state, which would
	 * be a bad idea.
	 */
	if (isconstraintarc(a) && hasconstraintout(sto)) {
	    struct state *prevclone;
	    int canmerge;
	    struct arc *a2;

	    /*
	     * Back-link constraint arcs must not be followed.  Nor is there a
	     * need to revisit states previously merged into this clone.
	     */
	    assert(sto->no < nstates);
	    if (donemap[sto->no] != 0) {
		continue;
	    }

	    /*
	     * Check whether we already have a child clone state for this
	     * source state.
	     */
	    prevclone = NULL;
	    for (a2 = sclone->outs; a2 != NULL; a2 = a2->outchain) {
		if (a2->to->tmp == sto) {
		    prevclone = a2->to;
		    break;
		}
	    }

	    /*
	     * If this arc is labeled the same as refarc, or the same as any
	     * arc we must have traversed to get to sclone, then no additional
	     * constraints need to be met to get to sto, so we should just
	     * merge its outarcs into sclone.
	     */
	    if (refarc && a->type == refarc->type && a->co == refarc->co) {
		canmerge = 1;
	    } else {
		struct state *s;

		canmerge = 0;
		for (s = sclone; s->ins; s = s->ins->from) {
		    if (s->nins == 1 &&
			    a->type == s->ins->type && a->co == s->ins->co) {
			canmerge = 1;
			break;
		    }
		}
	    }

	    if (canmerge) {
		/*
		 * We can merge into sclone.  If we previously made a child
		 * clone state, drop it; there's no need to visit it.  (This
		 * can happen if ssource has multiple pathways to sto, and we
		 * only just now found one that is provably a no-op.)
		 */
		if (prevclone) {
		    dropstate(nfa, prevclone);	/* kills our outarc, too */
		}

		/* Recurse to merge sto's outarcs into sclone */
		clonesuccessorstates(nfa, sto, sclone, spredecessor, refarc,
			donemap, outerdonemap, nstates);
		/* sto should now be marked as previously visited */
		assert(NISERR() || donemap[sto->no] == 1);
	    } else if (prevclone) {
		/*
		 * We already have a clone state for this successor, so just
		 * make another arc to it.
		 */
		cparc(nfa, a, sclone, prevclone);
	    } else {
		/*
		 * We need to create a new successor clone state.
		 */
		struct state *stoclone;

		stoclone = newstate(nfa);
		if (stoclone == NULL) {
		    assert(NISERR());
		    break;
		}
		/* Mark it as to what it's a clone of */
		stoclone->tmp = sto;
		/* ... and add the outarc leading to it */
		cparc(nfa, a, sclone, stoclone);
	    }
	} else {
	    /*
	     * Non-constraint outarcs just get copied to sclone, as do outarcs
	     * leading to states with no constraint outarc.
	     */
	    cparc(nfa, a, sclone, sto);
	}
    }

    /*
     * If we are at outer level for this clone state, recurse to all its child
     * clone states, clearing their tmp fields as we go.  (If we're not
     * outermost for sclone, leave this to be done by the outer call level.)
     * Note that if we have multiple outarcs leading to the same clone state,
     * it will only be recursed-to once.
     */
    if (curdonemap == NULL) {
	for (a = sclone->outs; a != NULL && !NISERR(); a = a->outchain) {
	    struct state *stoclone = a->to;
	    struct state *sto = stoclone->tmp;

	    if (sto != NULL) {
		stoclone->tmp = NULL;
		clonesuccessorstates(nfa, sto, stoclone, spredecessor, refarc,
			NULL, donemap, nstates);
	    }
	}

	/* Don't forget to free sclone's donemap when done with it */
	FREE(donemap);
    }
}
 
/*
 - cleanup - clean up NFA after optimizations
 ^ static void cleanup(struct nfa *);
 */
static void
................................................................................
	    }
	}
    }
    return 0;
}
 
/*
 - compact - construct the compact representation of an NFA
 ^ static void compact(struct nfa *, struct cnfa *);
 */
static void
compact(
    struct nfa *nfa,
    struct cnfa *cnfa)
{
................................................................................
		assert(s->no != cnfa->pre);
		ca->co = (color) (cnfa->ncolors + a->co);
		ca->to = a->to->no;
		ca++;
		cnfa->flags |= HASLACONS;
		break;
	    default:
		NERR(REG_ASSERT);
		break;
	    }
	}
	carcsort(first, ca - first);
	ca->co = COLORLESS;
	ca->to = 0;
	ca++;
    }
    assert(ca == &cnfa->arcs[narcs]);
    assert(cnfa->nstates != 0);

................................................................................
	cnfa->stflags[a->to->no] = CNFA_NOPROGRESS;
    }
    cnfa->stflags[nfa->pre->no] = CNFA_NOPROGRESS;
}
 
/*
 - carcsort - sort compacted-NFA arcs by color


 ^ static void carcsort(struct carc *, struct carc *);
 */
static void
carcsort(
    struct carc *first,
    size_t n)
{
    if (n > 1) {
	qsort(first, n, sizeof(struct carc), carc_cmp);

    }


}

static int
carc_cmp(
    const void *a,
    const void *b)

{
    const struct carc *aa = (const struct carc *) a;
    const struct carc *bb = (const struct carc *) b;

  
    if (aa->co < bb->co) {
	return -1;
    }
    if (aa->co > bb->co) {
	return +1;
    }
    if (aa->to < bb->to) {
	return -1;
    }
    if (aa->to > bb->to) {
	return +1;
    }
    return 0;
}
 
/*
 - freecnfa - free a compacted NFA
 ^ static void freecnfa(struct cnfa *);
 */
static void
................................................................................
static void
dumpnfa(
    struct nfa *nfa,
    FILE *f)
{
#ifdef REG_DEBUG
    struct state *s;
    int nstates = 0;
    int narcs = 0;

    fprintf(f, "pre %d, post %d", nfa->pre->no, nfa->post->no);
    if (nfa->bos[0] != COLORLESS) {
	fprintf(f, ", bos [%ld]", (long) nfa->bos[0]);
    }
    if (nfa->bos[1] != COLORLESS) {
	fprintf(f, ", bol [%ld]", (long) nfa->bos[1]);
................................................................................
    }
    if (nfa->eos[1] != COLORLESS) {
	fprintf(f, ", eol [%ld]", (long) nfa->eos[1]);
    }
    fprintf(f, "\n");
    for (s = nfa->states; s != NULL; s = s->next) {
	dumpstate(s, f);
	nstates++;
	narcs += s->nouts;
    }
    fprintf(f, "total of %d states, %d arcs\n", nstates, narcs);
    if (nfa->parent == NULL) {
	dumpcolors(nfa->cm, f);
    }
    fflush(f);
#endif
}
 
................................................................................
 */
static void
dumparcs(
    struct state *s,
    FILE *f)
{
    int pos;















    struct arc *a;




    /* printing oldest arcs first is usually clearer */
    a = s->outs;
    assert(a != NULL);
    while (a->outchain != NULL) {

	a = a->outchain;
    }
    pos = 1;
    do {
	dumparc(a, s, f);
	if (pos == 5) {
	    fprintf(f, "\n");
	    pos = 1;
	} else {
	    pos++;
	}

	a = a->outchainRev;
    } while (a != NULL);
    if (pos != 1) {
	fprintf(f, "\n");
    }
}
 
/*
 - dumparc - dump one outarc in readable form, including prefixing tab
 ^ static void dumparc(struct arc *, struct state *, FILE *);
 */
static void
dumparc(

Changes to generic/regcomp.c.

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static void freenfa(struct nfa *);
static struct state *newstate(struct nfa *);
static struct state *newfstate(struct nfa *, int flag);
static void dropstate(struct nfa *, struct state *);
static void freestate(struct nfa *, struct state *);
static void destroystate(struct nfa *, struct state *);
static void newarc(struct nfa *, int, pcolor, struct state *, struct state *);

static struct arc *allocarc(struct nfa *, struct state *);
static void freearc(struct nfa *, struct arc *);

static int hasnonemptyout(struct state *);
static int nonemptyouts(struct state *);
static int nonemptyins(struct state *);
static struct arc *findarc(struct state *, int, pcolor);
static void cparc(struct nfa *, struct arc *, struct state *, struct state *);




static void moveins(struct nfa *, struct state *, struct state *);
static void copyins(struct nfa *, struct state *, struct state *, int);

static void moveouts(struct nfa *, struct state *, struct state *);
static void copyouts(struct nfa *, struct state *, struct state *, int);
static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int);
static void delsub(struct nfa *, struct state *, struct state *);
static void deltraverse(struct nfa *, struct state *, struct state *);
static void dupnfa(struct nfa *, struct state *, struct state *, struct state *, struct state *);
static void duptraverse(struct nfa *, struct state *, struct state *, int);
static void cleartraverse(struct nfa *, struct state *);
static void specialcolors(struct nfa *);
static long optimize(struct nfa *, FILE *);
static void pullback(struct nfa *, FILE *);
static int pull(struct nfa *, struct arc *);
static void pushfwd(struct nfa *, FILE *);
static int push(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(struct arc *, struct arc *);
static void fixempties(struct nfa *, FILE *);
static struct state *emptyreachable(struct state *, struct state *);






static void replaceempty(struct nfa *, struct state *, struct state *);

static void cleanup(struct nfa *);
static void markreachable(struct nfa *, struct state *, struct state *, struct state *);
static void markcanreach(struct nfa *, struct state *, struct state *, struct state *);
static long analyze(struct nfa *);
static void compact(struct nfa *, struct cnfa *);
static void carcsort(struct carc *, struct carc *);

static void freecnfa(struct cnfa *);
static void dumpnfa(struct nfa *, FILE *);
#ifdef REG_DEBUG
static void dumpstate(struct state *, FILE *);
static void dumparcs(struct state *, FILE *);
static int dumprarcs(struct arc *, struct state *, FILE *, int);
static void dumparc(struct arc *, struct state *, FILE *);
#endif
static void dumpcnfa(struct cnfa *, FILE *);
#ifdef REG_DEBUG
static void dumpcstate(int, struct cnfa *, FILE *);
#endif
/* === regc_cvec.c === */
................................................................................
    struct subre *treechain;	/* all tree nodes allocated */
    struct subre *treefree;	/* any free tree nodes */
    int ntree;			/* number of tree nodes, plus one */
    struct cvec *cv;		/* interface cvec */
    struct cvec *cv2;		/* utility cvec */
    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? */
................................................................................
    v->tree = NULL;
    v->treechain = NULL;
    v->treefree = NULL;
    v->cv = NULL;
    v->cv2 = 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);

    /*
................................................................................

    /*
     * Do the splits.
     */

    for (s=slist ; s!=NULL ; s=s2) {
	s2 = newstate(nfa);


	copyouts(nfa, s, s2, 1);

	for (a=s->ins ; a!=NULL ; a=b) {
	    b = a->inchain;

	    if (a->from != pre) {
		cparc(nfa, a, a->from, s2);
		freearc(nfa, a);
	    }
................................................................................

    fprintf(f, "\n\n\n========= DUMP ==========\n");
    fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n",
	    (int) 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);
    }






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static void freenfa(struct nfa *);
static struct state *newstate(struct nfa *);
static struct state *newfstate(struct nfa *, int flag);
static void dropstate(struct nfa *, struct state *);
static void freestate(struct nfa *, struct state *);
static void destroystate(struct nfa *, struct state *);
static void newarc(struct nfa *, int, pcolor, struct state *, struct state *);
static void createarc(struct nfa *, int, pcolor, struct state *, struct state *);
static struct arc *allocarc(struct nfa *, struct state *);
static void freearc(struct nfa *, struct arc *);
static void changearctarget(struct arc *, struct state *);
static int hasnonemptyout(struct state *);


static struct arc *findarc(struct state *, int, pcolor);
static void cparc(struct nfa *, struct arc *, struct state *, struct state *);
static void sortins(struct nfa *, struct state *);
static int sortins_cmp(const void *, const void *);
static void sortouts(struct nfa *, struct state *);
static int sortouts_cmp(const void *, const void *);
static void moveins(struct nfa *, struct state *, struct state *);
static void copyins(struct nfa *, struct state *, struct state *);
static void mergeins(struct nfa *, struct state *, struct arc **, int);
static void moveouts(struct nfa *, struct state *, struct state *);
static void copyouts(struct nfa *, struct state *, struct state *);
static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int);
static void delsub(struct nfa *, struct state *, struct state *);
static void deltraverse(struct nfa *, struct state *, struct state *);
static void dupnfa(struct nfa *, struct state *, struct state *, struct state *, struct state *);
static void duptraverse(struct nfa *, struct state *, struct state *, int);
static void cleartraverse(struct nfa *, struct state *);
static void specialcolors(struct nfa *);
static long optimize(struct nfa *, FILE *);
static void pullback(struct nfa *, FILE *);
static int pull(struct nfa *, struct arc *, struct state **);
static void pushfwd(struct nfa *, FILE *);
static int push(struct nfa *, struct arc *, struct state **);
#define	INCOMPATIBLE	1	/* destroys arc */
#define	SATISFIED	2	/* constraint satisfied */
#define	COMPATIBLE	3	/* compatible but not satisfied yet */
static int combine(struct arc *, struct arc *);
static void fixempties(struct nfa *, FILE *);
static struct state *emptyreachable(struct nfa *, struct state *,
			struct state *, struct arc **);
static int	isconstraintarc(struct arc *);
static int	hasconstraintout(struct state *);
static void fixconstraintloops(struct nfa *, FILE *);
static int	findconstraintloop(struct nfa *, struct state *);
static void breakconstraintloop(struct nfa *, struct state *);
static void clonesuccessorstates(struct nfa *, struct state *, struct state *,
		 struct state *, struct arc *, char *, char *, int);
static void cleanup(struct nfa *);
static void markreachable(struct nfa *, struct state *, struct state *, struct state *);
static void markcanreach(struct nfa *, struct state *, struct state *, struct state *);
static long analyze(struct nfa *);
static void compact(struct nfa *, struct cnfa *);
static void carcsort(struct carc *, size_t);
static int carc_cmp(const void *, const void *);
static void freecnfa(struct cnfa *);
static void dumpnfa(struct nfa *, FILE *);
#ifdef REG_DEBUG
static void dumpstate(struct state *, FILE *);
static void dumparcs(struct state *, FILE *);

static void dumparc(struct arc *, struct state *, FILE *);
#endif
static void dumpcnfa(struct cnfa *, FILE *);
#ifdef REG_DEBUG
static void dumpcstate(int, struct cnfa *, FILE *);
#endif
/* === regc_cvec.c === */
................................................................................
    struct subre *treechain;	/* all tree nodes allocated */
    struct subre *treefree;	/* any free tree nodes */
    int ntree;			/* number of tree nodes, plus one */
    struct cvec *cv;		/* interface cvec */
    struct cvec *cv2;		/* utility cvec */
    struct subre *lacons;	/* lookahead-constraint vector */
    int nlacons;		/* size of lacons */
    size_t spaceused;		/* approx. space used for compilation */
};

/* 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? */
................................................................................
    v->tree = NULL;
    v->treechain = NULL;
    v->treefree = NULL;
    v->cv = NULL;
    v->cv2 = NULL;
    v->lacons = NULL;
    v->nlacons = 0;
    v->spaceused = 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);

    /*
................................................................................

    /*
     * Do the splits.
     */

    for (s=slist ; s!=NULL ; s=s2) {
	s2 = newstate(nfa);

	NOERR();
	copyouts(nfa, s, s2);
	NOERR();
	for (a=s->ins ; a!=NULL ; a=b) {
	    b = a->inchain;

	    if (a->from != pre) {
		cparc(nfa, a, a->from, s2);
		freearc(nfa, a);
	    }
................................................................................

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

    dumpcolors(&g->cmap, f);
    if (!NULLCNFA(g->search)) {
	fprintf(f, "\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);
    }

Changes to generic/regerrs.h.

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{ REG_ERANGE,	"REG_ERANGE",	"invalid character range" },
{ REG_ESPACE,	"REG_ESPACE",	"out of memory" },
{ REG_BADRPT,	"REG_BADRPT",	"quantifier operand invalid" },
{ REG_ASSERT,	"REG_ASSERT",	"\"can't happen\" -- you found a bug" },
{ REG_INVARG,	"REG_INVARG",	"invalid argument to regex function" },
{ REG_MIXED,	"REG_MIXED",	"character widths of regex and string differ" },
{ REG_BADOPT,	"REG_BADOPT",	"invalid embedded option" },
{ REG_ETOOBIG,	"REG_ETOOBIG",	"nfa has too many states" },
{ REG_ECOLORS,	"REG_ECOLORS",	"too many colors" },






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{ REG_ERANGE,	"REG_ERANGE",	"invalid character range" },
{ REG_ESPACE,	"REG_ESPACE",	"out of memory" },
{ REG_BADRPT,	"REG_BADRPT",	"quantifier operand invalid" },
{ REG_ASSERT,	"REG_ASSERT",	"\"can't happen\" -- you found a bug" },
{ REG_INVARG,	"REG_INVARG",	"invalid argument to regex function" },
{ REG_MIXED,	"REG_MIXED",	"character widths of regex and string differ" },
{ REG_BADOPT,	"REG_BADOPT",	"invalid embedded option" },
{ REG_ETOOBIG,	"REG_ETOOBIG",	"regular expression is too complex" },
{ REG_ECOLORS,	"REG_ECOLORS",	"too many colors" },

Changes to generic/regex.h.

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#define	REG_ERANGE	11	/* invalid character range */
#define	REG_ESPACE	12	/* out of memory */
#define	REG_BADRPT	13	/* quantifier operand invalid */
#define	REG_ASSERT	15	/* "can't happen" -- you found a bug */
#define	REG_INVARG	16	/* invalid argument to regex function */
#define	REG_MIXED	17	/* character widths of regex and string differ */
#define	REG_BADOPT	18	/* invalid embedded option */
#define	REG_ETOOBIG	19	/* nfa has too many states */
#define	REG_ECOLORS	20	/* too many colors */
/* two specials for debugging and testing */
#define	REG_ATOI	101	/* convert error-code name to number */
#define	REG_ITOA	102	/* convert error-code number to name */

/*
 * the prototypes, as possibly munched by regfwd






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#define	REG_ERANGE	11	/* invalid character range */
#define	REG_ESPACE	12	/* out of memory */
#define	REG_BADRPT	13	/* quantifier operand invalid */
#define	REG_ASSERT	15	/* "can't happen" -- you found a bug */
#define	REG_INVARG	16	/* invalid argument to regex function */
#define	REG_MIXED	17	/* character widths of regex and string differ */
#define	REG_BADOPT	18	/* invalid embedded option */
#define	REG_ETOOBIG	19	/* regular expression is too complex */
#define	REG_ECOLORS	20	/* too many colors */
/* two specials for debugging and testing */
#define	REG_ATOI	101	/* convert error-code name to number */
#define	REG_ITOA	102	/* convert error-code number to name */

/*
 * the prototypes, as possibly munched by regfwd

Changes to generic/regguts.h.

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struct arc {
    int type;			/* 0 if free, else an NFA arc type code */
    color co;
    struct state *from;		/* where it's from (and contained within) */
    struct state *to;		/* where it's to */
    struct arc *outchain;	/* link in *from's outs chain or free chain */

#define	freechain	outchain
    struct arc *inchain;	/* link in *to's ins chain */

    struct arc *colorchain;	/* link in color's arc chain */
    struct arc *colorchainRev;	/* back-link in color's arc chain */
};

struct arcbatch {		/* for bulk allocation of arcs */
    struct arcbatch *next;
#define	ABSIZE	10
    struct arc a[ABSIZE];
................................................................................
    int nstates;		/* for numbering states */
    struct state *states;	/* state-chain header */
    struct state *slast;	/* tail of the chain */
    struct state *free;		/* free list */
    struct colormap *cm;	/* the color map */
    color bos[2];		/* colors, if any, assigned to BOS and BOL */
    color eos[2];		/* colors, if any, assigned to EOS and EOL */
    size_t size;		/* Current NFA size; differs from nstates as
				 * it also counts the number of states created
				 * by children of this state. */
    struct vars *v;		/* simplifies compile error reporting */
    struct nfa *parent;		/* parent NFA, if any */
};

/*
 * definitions for compacted NFA
 *
................................................................................
    /* states[n] are pointers into a single malloc'd array of arcs */
    struct carc *arcs;		/* the area for the lists */
};
#define	ZAPCNFA(cnfa)	((cnfa).nstates = 0)
#define	NULLCNFA(cnfa)	((cnfa).nstates == 0)

/*
 * Used to limit the maximum NFA size to something sane. [Bug 1810264]





 */

#ifndef REG_MAX_STATES
#   define REG_MAX_STATES	100000

#endif

/*
 * subexpression tree
 *
 * "op" is one of:
 *	'='  plain regex without interesting substructure (implemented as DFA)






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struct arc {
    int type;			/* 0 if free, else an NFA arc type code */
    color co;
    struct state *from;		/* where it's from (and contained within) */
    struct state *to;		/* where it's to */
    struct arc *outchain;	/* link in *from's outs chain or free chain */
    struct arc *outchainRev;	/* back-link in *from's outs chain */
#define	freechain outchain	/* we do not maintain "freechainRev" */
    struct arc *inchain;	/* *to's ins chain */
    struct arc *inchainRev;	/* back-link in *to's ins chain */
    struct arc *colorchain;	/* color's arc chain */
    struct arc *colorchainRev;	/* back-link in color's arc chain */
};

struct arcbatch {		/* for bulk allocation of arcs */
    struct arcbatch *next;
#define	ABSIZE	10
    struct arc a[ABSIZE];
................................................................................
    int nstates;		/* for numbering states */
    struct state *states;	/* state-chain header */
    struct state *slast;	/* tail of the chain */
    struct state *free;		/* free list */
    struct colormap *cm;	/* the color map */
    color bos[2];		/* colors, if any, assigned to BOS and BOL */
    color eos[2];		/* colors, if any, assigned to EOS and EOL */



    struct vars *v;		/* simplifies compile error reporting */
    struct nfa *parent;		/* parent NFA, if any */
};

/*
 * definitions for compacted NFA
 *
................................................................................
    /* states[n] are pointers into a single malloc'd array of arcs */
    struct carc *arcs;		/* the area for the lists */
};
#define	ZAPCNFA(cnfa)	((cnfa).nstates = 0)
#define	NULLCNFA(cnfa)	((cnfa).nstates == 0)

/*
 * This symbol limits the transient heap space used by the regex compiler,
 * and thereby also the maximum complexity of NFAs that we'll deal with.
 * Currently we only count NFA states and arcs against this; the other
 * transient data is generally not large enough to notice compared to those.
 * Note that we do not charge anything for the final output data structures
 * (the compacted NFA and the colormap).
 */

#ifndef REG_MAX_COMPILE_SPACE
#define REG_MAX_COMPILE_SPACE  \
	(100000 * sizeof(struct state) + 100000 * sizeof(struct arcbatch))
#endif

/*
 * subexpression tree
 *
 * "op" is one of:
 *	'='  plain regex without interesting substructure (implemented as DFA)

Changes to tests/reg.test.

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test reg-33.13 {Bug 1810264 - infinite loop} {
    regexp {($|^)*} {x}
} 1
# Some environments have small default stack sizes. [Bug 1905562]
test reg-33.14 {Bug 1810264 - super-expensive expression} nonPortable {
    regexp {(x{200}){200}$y} {x}
} 0

test reg-33.15 {Bug 3603557 - an "in the wild" RE} {
    lindex [regexp -expanded -about {
	^TETRA_MODE_CMD				# Message Type
	([[:blank:]]+)				# Pad
	(ETS_1_1|ETS_1_2|ETS_2_2)		# SystemCode
	([[:blank:]]+)				# Pad
	(CONTINUOUS|CARRIER|MCCH|TRAFFIC)	# SharingMode
	([[:blank:]]+)				# Pad
................................................................................
	([0-7])					# MinPriority
	([[:blank:]]+)				# Pad
	(PASS|TRUE|FAIL|FALSE)			# ExtdSrvcsEnabled
	([[:blank:]]+)				# Pad
	(.*)					# ConditionalFields
    }] 0
} 68
test reg-33.16 {Bug [8d2c0da36d]- another "in the wild" RE} {
    lindex [regexp -about "^MRK:client1: =1339 14HKelly Talisman 10011000 (\[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]*) \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 8 0 8 0 0 0 77 77 1 1 2 0 11 { 1 3 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 13HC6 My Creator 2 3 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 31HC7 Slightly offensive name, huh 3 8 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 23HE-mail:[email protected] 4 9 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 17Hcompface must die 5 10 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 0 3HAir 6 12 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 14HPGP public key 7 13 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 [email protected] 8 30 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 0 12H2 text/plain 9 30 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 0 13H2 x-kom/basic 10 33 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 1H0 11 14 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 1H3 }\r?"] 0
} 1
 




















































# cleanup
::tcltest::cleanupTests
return

# Local Variables:
# mode: tcl
# End:






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test reg-33.13 {Bug 1810264 - infinite loop} {
    regexp {($|^)*} {x}
} 1
# Some environments have small default stack sizes. [Bug 1905562]
test reg-33.14 {Bug 1810264 - super-expensive expression} nonPortable {
    regexp {(x{200}){200}$y} {x}
} 0

test reg-33.15.1 {Bug 3603557 - an "in the wild" RE} {
    lindex [regexp -expanded -about {
	^TETRA_MODE_CMD				# Message Type
	([[:blank:]]+)				# Pad
	(ETS_1_1|ETS_1_2|ETS_2_2)		# SystemCode
	([[:blank:]]+)				# Pad
	(CONTINUOUS|CARRIER|MCCH|TRAFFIC)	# SharingMode
	([[:blank:]]+)				# Pad
................................................................................
	([0-7])					# MinPriority
	([[:blank:]]+)				# Pad
	(PASS|TRUE|FAIL|FALSE)			# ExtdSrvcsEnabled
	([[:blank:]]+)				# Pad
	(.*)					# ConditionalFields
    }] 0
} 68
test reg-33.16.1 {Bug [8d2c0da36d]- another "in the wild" RE} {
    lindex [regexp -about "^MRK:client1: =1339 14HKelly Talisman 10011000 (\[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]*) \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 8 0 8 0 0 0 77 77 1 1 2 0 11 { 1 3 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 13HC6 My Creator 2 3 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 31HC7 Slightly offensive name, huh 3 8 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 23HE-mail:[email protected] 4 9 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 17Hcompface must die 5 10 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 0 3HAir 6 12 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 14HPGP public key 7 13 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 [email protected] 8 30 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 0 12H2 text/plain 9 30 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 0 13H2 x-kom/basic 10 33 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 1H0 11 14 8 \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* \[0-9\]* 00000000 1 1H3 }\r?"] 0
} 1

test reg-33.15 {constraint fixes} {
    regexp {(^)+^} x
} 1
test reg-33.16 {constraint fixes} {
    regexp {($^)+} x
} 0
test reg-33.17 {constraint fixes} {
    regexp {(^$)*} x
} 1
test reg-33.18 {constraint fixes} {
    regexp {(^(?!aa))+} {aa bb cc}
} 0
test reg-33.19 {constraint fixes} {
    regexp {(^(?!aa)(?!bb)(?!cc))+} {aa x}
} 0
test reg-33.20 {constraint fixes} {
    regexp {(^(?!aa)(?!bb)(?!cc))+} {bb x}
} 0
test reg-33.21 {constraint fixes} {
    regexp {(^(?!aa)(?!bb)(?!cc))+} {cc x}
} 0
test reg-33.22 {constraint fixes} {
    regexp {(^(?!aa)(?!bb)(?!cc))+} {dd x}
} 1

test reg-33.23 {} {
    regexp {abcd(\m)+xyz} x
} 0
test reg-33.24 {} {
    regexp {abcd(\m)+xyz} a
} 0
test reg-33.25 {} {
    regexp {^abcd*(((((^(a c(e?d)a+|)+|)+|)+|)+|a)+|)} x
} 0
test reg-33.26 {} {
    regexp {a^(^)bcd*xy(((((($a+|)+|)+|)+$|)+|)+|)^$} x
} 0
test reg-33.27 {} {
    regexp {xyz(\Y\Y)+} x
} 0
test reg-33.28 {} {
    regexp {x|(?:\M)+} x
} 1
test reg-33.29 {} {
    # This is near the limits of the RE engine
    regexp [string repeat x*y*z* 480] x
} 1

test reg-33.30 {Bug 1080042} {
    regexp {(\Y)+} foo
} 1

# cleanup
::tcltest::cleanupTests
return

# Local Variables:
# mode: tcl
# End:

Changes to tests/regexp.test.

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	[a 667]([a 55])[a 668]([a 55])[a 669]([a 55])[a 668]([a 55]) \
	[a 671]([a 55])[a 669]([a 55])[a 668]([a 55])[a 669]([a 55]) \
	[a 669]([a 55])[a 669]([a 55])[a 668]([a 55])[a 669]([a 55]) \
	[a 668]([a 55])[a 710]([a 55])[a 668]([a 55])[a 668]([a 55]) \
	[a 668]([a 55])[a 668]([a 55])[a 668]([a 55])[a 511]] {}] a
} -cleanup {
    rename a {}
} -returnCodes 1 -result {couldn't compile regular expression pattern: nfa has too many states}
test regexp-22.5 {Bug 3610026} -setup {
    set e {}
    set cp 99
    while {$cp < 32864} {
	append e [format %c [incr cp]]
    }
} -body {






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	[a 667]([a 55])[a 668]([a 55])[a 669]([a 55])[a 668]([a 55]) \
	[a 671]([a 55])[a 669]([a 55])[a 668]([a 55])[a 669]([a 55]) \
	[a 669]([a 55])[a 669]([a 55])[a 668]([a 55])[a 669]([a 55]) \
	[a 668]([a 55])[a 710]([a 55])[a 668]([a 55])[a 668]([a 55]) \
	[a 668]([a 55])[a 668]([a 55])[a 668]([a 55])[a 511]] {}] a
} -cleanup {
    rename a {}
} -returnCodes 1 -match glob -result {couldn't compile regular expression pattern: *}
test regexp-22.5 {Bug 3610026} -setup {
    set e {}
    set cp 99
    while {$cp < 32864} {
	append e [format %c [incr cp]]
    }
} -body {