regc_nfa.c File Reference

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Macros
#define	NISERR()   VISERR(nfa->v)
#define	NERR(e)   VERR(nfa->v, (e))
#define	BULK_ARC_OP_USE_SORT(nsrcarcs, ndestarcs)    ((nsrcarcs) < 4 ? 0 : ((nsrcarcs) > 32 || (ndestarcs) > 32))
#define	CA(ct, at)   (((ct)<<CHAR_BIT) | (at))

Functions
static struct nfa *	newnfa (struct vars *v, struct colormap *cm, struct nfa *parent)
static void	freenfa (struct nfa *nfa)
static struct state *	newstate (struct nfa *nfa)
static struct state *	newfstate (struct nfa *nfa, int flag)
static void	dropstate (struct nfa *nfa, struct state *s)
static void	freestate (struct nfa *nfa, struct state *s)
static void	newarc (struct nfa *nfa, int t, color co, struct state *from, struct state *to)
static void	createarc (struct nfa *nfa, int t, color co, struct state *from, struct state *to)
static struct arc *	allocarc (struct nfa *nfa)
static void	freearc (struct nfa *nfa, struct arc *victim)
static void	changearcsource (struct arc *a, struct state *newfrom)
static void	changearctarget (struct arc *a, struct state *newto)
static int	hasnonemptyout (struct state *s)
static struct arc *	findarc (struct state *s, int type, color co)
static void	cparc (struct nfa *nfa, struct arc *oa, struct state *from, struct state *to)
static void	sortins (struct nfa *nfa, struct state *s)
static int	sortins_cmp (const void *a, const void *b)
static void	sortouts (struct nfa *nfa, struct state *s)
static int	sortouts_cmp (const void *a, const void *b)
static void	moveins (struct nfa *nfa, struct state *oldState, struct state *newState)
static void	copyins (struct nfa *nfa, struct state *oldState, struct state *newState)
static void	mergeins (struct nfa *nfa, struct state *s, struct arc **arcarray, int arccount)
static void	moveouts (struct nfa *nfa, struct state *oldState, struct state *newState)
static void	copyouts (struct nfa *nfa, struct state *oldState, struct state *newState)
static void	cloneouts (struct nfa *nfa, struct state *old, struct state *from, struct state *to, int type)
static void	delsub (struct nfa *nfa, struct state *lp, struct state *rp)
static void	deltraverse (struct nfa *nfa, struct state *leftend, struct state *s)
static void	dupnfa (struct nfa *nfa, struct state *start, struct state *stop, struct state *from, struct state *to)
static void	duptraverse (struct nfa *nfa, struct state *s, struct state *stmp)
static void	removeconstraints (struct nfa *nfa, struct state *start, struct state *stop)
static void	removetraverse (struct nfa *nfa, struct state *s)
static void	cleartraverse (struct nfa *nfa, struct state *s)
static struct state *	single_color_transition (struct state *s1, struct state *s2)
static void	specialcolors (struct nfa *nfa)
static long	optimize (struct nfa *nfa, FILE *f)
static void	pullback (struct nfa *nfa, FILE *f)
static int	pull (struct nfa *nfa, struct arc *con, struct state **intermediates)
static void	pushfwd (struct nfa *nfa, FILE *f)
static int	push (struct nfa *nfa, struct arc *con, struct state **intermediates)
static int	combine (struct nfa *nfa, struct arc *con, struct arc *a)
static void	fixempties (struct nfa *nfa, FILE *f)
static struct state *	emptyreachable (struct nfa *nfa, struct state *s, struct state *lastfound, struct arc **inarcsorig)
static int	isconstraintarc (struct arc *a)
static int	hasconstraintout (struct state *s)
static void	fixconstraintloops (struct nfa *nfa, FILE *f)
static int	findconstraintloop (struct nfa *nfa, struct state *s)
static void	breakconstraintloop (struct nfa *nfa, struct state *sinitial)
static void	clonesuccessorstates (struct nfa *nfa, struct state *ssource, struct state *sclone, struct state *spredecessor, struct arc *refarc, char *curdonemap, char *outerdonemap, int nstates)
static void	removecantmatch (struct nfa *nfa)
static void	cleanup (struct nfa *nfa)
static void	markreachable (struct nfa *nfa, struct state *s, struct state *okay, struct state *mark)
static void	markcanreach (struct nfa *nfa, struct state *s, struct state *okay, struct state *mark)
static long	analyze (struct nfa *nfa)
static void	checkmatchall (struct nfa *nfa)
static bool	checkmatchall_recurse (struct nfa *nfa, struct state *s, bool **haspaths)
static bool	check_out_colors_match (struct state *s, color co1, color co2)
static bool	check_in_colors_match (struct state *s, color co1, color co2)
static void	compact (struct nfa *nfa, struct cnfa *cnfa)
static void	carcsort (struct carc *first, size_t n)
static int	carc_cmp (const void *a, const void *b)
static void	freecnfa (struct cnfa *cnfa)
static void	dumpnfa (struct nfa *nfa, FILE *f)

Macro Definition Documentation

BULK_ARC_OP_USE_SORT

#define BULK_ARC_OP_USE_SORT	(		nsrcarcs,
			ndestarcs
	)		((nsrcarcs) < 4 ? 0 : ((nsrcarcs) > 32 || (ndestarcs) > 32))

Definition at line 758 of file regc_nfa.c.

                        : ((nsrcarcs) > 32 || (ndestarcs) > 32))

CA

#define CA	(		ct,
			at
	)		(((ct)<<CHAR_BIT) | (at))

NERR

#define NERR

(

e

)

VERR(nfa->v, (e))

Definition at line 40 of file regc_nfa.c.

NISERR

#define NISERR

(

)

VISERR(nfa->v)

Definition at line 39 of file regc_nfa.c.

Function Documentation

allocarc()

static struct arc * allocarc ( struct nfa *  nfa )

static

Definition at line 368 of file regc_nfa.c.

{
    struct arc *a;
 
    /* first, recycle anything that's on the freelist */
    if (nfa->freearcs != NULL)
    {
        a = nfa->freearcs;
        nfa->freearcs = a->freechain;
    }
    /* otherwise, is there anything left in the last arcbatch? */
    else if (nfa->lastab != NULL && nfa->lastabused < nfa->lastab->narcs)
    {
        a = &nfa->lastab->a[nfa->lastabused++];
    }
    /* otherwise, need to allocate a new arcbatch */
    else
    {
        struct arcbatch *newAb;
        size_t      narcs;
 
        if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE)
        {
            NERR(REG_ETOOBIG);
            return NULL;
        }
        narcs = (nfa->lastab != NULL) ? nfa->lastab->narcs * 2 : FIRSTABSIZE;
        if (narcs > MAXABSIZE)
            narcs = MAXABSIZE;
        newAb = (struct arcbatch *) MALLOC(ARCBATCHSIZE(narcs));
        if (newAb == NULL)
        {
            NERR(REG_ESPACE);
            return NULL;
        }
        nfa->v->spaceused += ARCBATCHSIZE(narcs);
        newAb->narcs = narcs;
        newAb->next = nfa->lastab;
        nfa->lastab = newAb;
        nfa->lastabused = 1;
        a = &newAb->a[0];
    }
 
    return a;
}

References a, arcbatch::a, ARCBATCHSIZE, fb(), FIRSTABSIZE, nfa::freearcs, nfa::lastab, nfa::lastabused, MALLOC, MAXABSIZE, arcbatch::narcs, NERR, REG_ESPACE, REG_ETOOBIG, REG_MAX_COMPILE_SPACE, vars::spaceused, and nfa::v.

Referenced by createarc().

analyze()

static long analyze ( struct nfa *  nfa )

static

Definition at line 3051 of file regc_nfa.c.

{
    struct arc *a;
    struct arc *aa;
 
    if (NISERR())
        return 0;
 
    /* Detect whether NFA can't match anything */
    if (nfa->pre->outs == NULL)
        return REG_UIMPOSSIBLE;
 
    /* Detect whether NFA matches all strings (possibly with length bounds) */
    checkmatchall(nfa);
 
    /* Detect whether NFA can possibly match a zero-length string */
    for (a = nfa->pre->outs; a != NULL; a = a->outchain)
        for (aa = a->to->outs; aa != NULL; aa = aa->outchain)
            if (aa->to == nfa->post)
                return REG_UEMPTYMATCH;
    return 0;
}

References a, checkmatchall(), fb(), NISERR, state::outs, nfa::post, nfa::pre, REG_UEMPTYMATCH, and REG_UIMPOSSIBLE.

Referenced by ExecVacuum(), GetCommandLogLevel(), and optimize().

breakconstraintloop()

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

static

Definition at line 2558 of file regc_nfa.c.

{
    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;
        }
    }
}

References a, assert, clonesuccessorstates(), cparc(), fb(), freearc(), freestate(), isconstraintarc(), newstate(), state::next, NISERR, nfa::nstates, state::outs, nfa::states, and state::tmp.

Referenced by findconstraintloop().

carc_cmp()

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

static

Definition at line 3612 of file regc_nfa.c.

{
    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;
    /* This is unreached, since there should be no duplicate arcs now: */
    return 0;
}

References a, b, and fb().

Referenced by carcsort().

carcsort()

static void carcsort ( struct carc *  first, size_t  n  )

static

Definition at line 3605 of file regc_nfa.c.

{
    if (n > 1)
        qsort(first, n, sizeof(struct carc), carc_cmp);
}

References carc_cmp(), and qsort.

Referenced by compact().

changearcsource()

static void changearcsource ( struct arc *  a, struct state *  newfrom  )

static

Definition at line 489 of file regc_nfa.c.

{
    struct state *oldfrom = a->from;
    struct arc *predecessor;
 
    assert(oldfrom != newfrom);
 
    /* take it off old source's out-chain */
    assert(oldfrom != NULL);
    predecessor = a->outchainRev;
    if (predecessor == NULL)
    {
        assert(oldfrom->outs == a);
        oldfrom->outs = a->outchain;
    }
    else
    {
        assert(predecessor->outchain == a);
        predecessor->outchain = a->outchain;
    }
    if (a->outchain != NULL)
    {
        assert(a->outchain->outchainRev == a);
        a->outchain->outchainRev = predecessor;
    }
    oldfrom->nouts--;
 
    a->from = newfrom;
 
    /* prepend it to new source's out-chain */
    a->outchain = newfrom->outs;
    a->outchainRev = NULL;
    if (newfrom->outs)
        newfrom->outs->outchainRev = a;
    newfrom->outs = a;
    newfrom->nouts++;
}

References a, assert, and fb().

Referenced by moveouts().

changearctarget()

static void changearctarget ( struct arc *  a, struct state *  newto  )

static

Definition at line 533 of file regc_nfa.c.

{
    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++;
}

References a, assert, and fb().

Referenced by moveins().

check_in_colors_match()

static bool check_in_colors_match ( struct state *  s, color  co1, color  co2  )

static

Definition at line 3469 of file regc_nfa.c.

{
    bool        result = true;
    struct arc *a;
 
    /*
     * Identical algorithm to check_out_colors_match, except examine the
     * from-states of s' inarcs.
     */
    for (a = s->ins; a != NULL; a = a->inchain)
    {
        if (a->co == co1)
        {
            assert(a->from->tmp == NULL);
            a->from->tmp = a->from;
        }
    }
    for (a = s->ins; a != NULL; a = a->inchain)
    {
        if (a->co == co2)
        {
            if (a->from->tmp != NULL)
                a->from->tmp = NULL;
            else
                result = false; /* unmatched co2 arc */
        }
    }
    for (a = s->ins; a != NULL; a = a->inchain)
    {
        if (a->co == co1)
        {
            if (a->from->tmp != NULL)
            {
                result = false; /* unmatched co1 arc */
                a->from->tmp = NULL;
            }
        }
    }
    return result;
}

References a, assert, fb(), and state::ins.

Referenced by checkmatchall().

check_out_colors_match()

static bool check_out_colors_match ( struct state *  s, color  co1, color  co2  )

static

Definition at line 3415 of file regc_nfa.c.

{
    bool        result = true;
    struct arc *a;
 
    /*
     * To do this in linear time, we assume that the NFA contains no duplicate
     * arcs.  Run through the out-arcs, marking states reachable by arcs of
     * color co1.  Run through again, un-marking states reachable by arcs of
     * color co2; if we see a not-marked state, we know this co2 arc is
     * unmatched.  Then run through again, checking for still-marked states,
     * and in any case leaving all the tmp fields reset to NULL.
     */
    for (a = s->outs; a != NULL; a = a->outchain)
    {
        if (a->co == co1)
        {
            assert(a->to->tmp == NULL);
            a->to->tmp = a->to;
        }
    }
    for (a = s->outs; a != NULL; a = a->outchain)
    {
        if (a->co == co2)
        {
            if (a->to->tmp != NULL)
                a->to->tmp = NULL;
            else
                result = false; /* unmatched co2 arc */
        }
    }
    for (a = s->outs; a != NULL; a = a->outchain)
    {
        if (a->co == co1)
        {
            if (a->to->tmp != NULL)
            {
                result = false; /* unmatched co1 arc */
                a->to->tmp = NULL;
            }
        }
    }
    return result;
}

References a, assert, fb(), and state::outs.

Referenced by checkmatchall().

checkmatchall()

static void checkmatchall ( struct nfa *  nfa )

static

Definition at line 3097 of file regc_nfa.c.

{
    bool      **haspaths;
    struct state *s;
    int         i;
 
    /*
     * If there are too many states, don't bother trying to detect matchall.
     * This limit serves to bound the time and memory we could consume below.
     * Note that even if the graph is all-RAINBOW, if there are significantly
     * more than DUPINF states then it's likely that there are paths of length
     * more than DUPINF, which would force us to fail anyhow.  In practice,
     * plausible ways of writing a matchall regex with maximum finite path
     * length K tend not to have very many more than K states.
     */
    if (nfa->nstates > DUPINF * 2)
        return;
 
    /*
     * First, scan all the states to verify that only RAINBOW arcs appear,
     * plus pseudocolor arcs adjacent to the pre and post states.  This lets
     * us quickly eliminate most cases that aren't matchall NFAs.
     */
    for (s = nfa->states; s != NULL; s = s->next)
    {
        struct arc *a;
 
        for (a = s->outs; a != NULL; a = a->outchain)
        {
            if (a->type != PLAIN)
                return;         /* any LACONs make it non-matchall */
            if (a->co != RAINBOW)
            {
                if (nfa->cm->cd[a->co].flags & PSEUDO)
                {
                    /*
                     * Pseudocolor arc: verify it's in a valid place (this
                     * seems quite unlikely to fail, but let's be sure).
                     */
                    if (s == nfa->pre &&
                        (a->co == nfa->bos[0] || a->co == nfa->bos[1]))
                         /* okay BOS/BOL arc */ ;
                    else if (a->to == nfa->post &&
                             (a->co == nfa->eos[0] || a->co == nfa->eos[1]))
                         /* okay EOS/EOL arc */ ;
                    else
                        return; /* unexpected pseudocolor arc */
                    /* We'll check these arcs some more below. */
                }
                else
                    return;     /* any other color makes it non-matchall */
            }
        }
        /* Also, assert that the tmp fields are available for use. */
        assert(s->tmp == NULL);
    }
 
    /*
     * The next cheapest check we can make is to verify that the BOS/BOL
     * outarcs of the pre state reach the same states as its RAINBOW outarcs.
     * If they don't, the NFA expresses some constraints on the character
     * before the matched string, making it non-matchall.  Likewise, the
     * EOS/EOL inarcs of the post state must match its RAINBOW inarcs.
     */
    if (!check_out_colors_match(nfa->pre, RAINBOW, nfa->bos[0]) ||
        !check_out_colors_match(nfa->pre, RAINBOW, nfa->bos[1]) ||
        !check_in_colors_match(nfa->post, RAINBOW, nfa->eos[0]) ||
        !check_in_colors_match(nfa->post, RAINBOW, nfa->eos[1]))
        return;
 
    /*
     * Initialize an array of path-length arrays, in which
     * checkmatchall_recurse will return per-state results.  This lets us
     * memo-ize the recursive search and avoid exponential time consumption.
     */
    haspaths = (bool **) MALLOC(nfa->nstates * sizeof(bool *));
    if (haspaths == NULL)
        return;                 /* fail quietly */
    memset(haspaths, 0, nfa->nstates * sizeof(bool *));
 
    /*
     * Recursively search the graph for all-RAINBOW paths to the "post" state,
     * starting at the "pre" state, and computing the lengths of the paths.
     * (Given the preceding checks, there should be at least one such path.
     * However we could get back a false result anyway, in case there are
     * multi-state loops, paths exceeding DUPINF+1 length, or non-algorithmic
     * failures such as ENOMEM.)
     */
    if (checkmatchall_recurse(nfa, nfa->pre, haspaths))
    {
        /* The useful result is the path length array for the pre state */
        bool       *haspath = haspaths[nfa->pre->no];
        int         minmatch,
                    maxmatch,
                    morematch;
 
        assert(haspath != NULL);
 
        /*
         * haspath[] now represents the set of possible path lengths; but we
         * want to reduce that to a min and max value, because it doesn't seem
         * worth complicating regexec.c to deal with nonconsecutive possible
         * match lengths.  Find min and max of first run of lengths, then
         * verify there are no nonconsecutive lengths.
         */
        for (minmatch = 0; minmatch <= DUPINF + 1; minmatch++)
        {
            if (haspath[minmatch])
                break;
        }
        assert(minmatch <= DUPINF + 1); /* else checkmatchall_recurse lied */
        for (maxmatch = minmatch; maxmatch < DUPINF + 1; maxmatch++)
        {
            if (!haspath[maxmatch + 1])
                break;
        }
        for (morematch = maxmatch + 1; morematch <= DUPINF + 1; morematch++)
        {
            if (haspath[morematch])
            {
                haspath = NULL; /* fail, there are nonconsecutive lengths */
                break;
            }
        }
 
        if (haspath != NULL)
        {
            /*
             * Success, so record the info.  Here we have a fine point: the
             * path length from the pre state includes the pre-to-initial
             * transition, so it's one more than the actually matched string
             * length.  (We avoided counting the final-to-post transition
             * within checkmatchall_recurse, but not this one.)  This is why
             * checkmatchall_recurse allows one more level of path length than
             * might seem necessary.  This decrement also takes care of
             * converting checkmatchall_recurse's definition of "infinity" as
             * "DUPINF+1" to our normal representation as "DUPINF".
             */
            assert(minmatch > 0);   /* else pre and post states were adjacent */
            nfa->minmatchall = minmatch - 1;
            nfa->maxmatchall = maxmatch - 1;
            nfa->flags |= MATCHALL;
        }
    }
 
    /* Clean up */
    for (i = 0; i < nfa->nstates; i++)
    {
        if (haspaths[i] != NULL)
            FREE(haspaths[i]);
    }
    FREE(haspaths);
}

References a, assert, nfa::bos, colormap::cd, check_in_colors_match(), check_out_colors_match(), checkmatchall_recurse(), nfa::cm, DUPINF, nfa::eos, fb(), colordesc::flags, nfa::flags, FREE, i, MALLOC, MATCHALL, nfa::maxmatchall, nfa::minmatchall, state::next, state::no, nfa::nstates, state::outs, PLAIN, nfa::post, nfa::pre, PSEUDO, RAINBOW, nfa::states, and state::tmp.

Referenced by analyze().

checkmatchall_recurse()

static bool checkmatchall_recurse ( struct nfa *  nfa, struct state *  s, bool **  haspaths  )

static

Definition at line 3277 of file regc_nfa.c.

{
    bool        result = false;
    bool        foundloop = false;
    bool       *haspath;
    struct arc *a;
 
    /*
     * Since this is recursive, it could be driven to stack overflow.  But we
     * need not treat that as a hard failure; just deem the NFA non-matchall.
     */
    if (STACK_TOO_DEEP(nfa->v->re))
        return false;
 
    /* In case the search takes a long time, check for cancel */
    INTERRUPT(nfa->v->re);
 
    /* Create a haspath array for this state */
    haspath = (bool *) MALLOC((DUPINF + 2) * sizeof(bool));
    if (haspath == NULL)
        return false;           /* again, treat as non-matchall */
    memset(haspath, 0, (DUPINF + 2) * sizeof(bool));
 
    /* Mark this state as being visited */
    assert(s->tmp == NULL);
    s->tmp = s;
 
    for (a = s->outs; a != NULL; a = a->outchain)
    {
        if (a->co != RAINBOW)
            continue;           /* ignore pseudocolor arcs */
        if (a->to == nfa->post)
        {
            /* We found an all-RAINBOW path to the post state */
            result = true;
 
            /*
             * Mark this state as being zero steps away from the string end
             * (the transition to the post state isn't counted).
             */
            haspath[0] = true;
        }
        else if (a->to == s)
        {
            /* We found a cycle of length 1, which we'll deal with below. */
            foundloop = true;
        }
        else if (a->to->tmp != NULL)
        {
            /* It's busy, so we found a cycle of length > 1, so fail. */
            result = false;
            break;
        }
        else
        {
            /* Consider paths forward through this to-state. */
            bool       *nexthaspath;
            int         i;
 
            /* If to-state was not already visited, recurse */
            if (haspaths[a->to->no] == NULL)
            {
                result = checkmatchall_recurse(nfa, a->to, haspaths);
                /* Fail if any recursive path fails */
                if (!result)
                    break;
            }
            else
            {
                /* The previous visit must have found path(s) to the end */
                result = true;
            }
            assert(a->to->tmp == NULL);
            nexthaspath = haspaths[a->to->no];
            assert(nexthaspath != NULL);
 
            /*
             * Now, for every path of length i from a->to to the string end,
             * there is a path of length i + 1 from s to the string end.
             */
            if (nexthaspath[DUPINF] != nexthaspath[DUPINF + 1])
            {
                /*
                 * a->to has a path of length exactly DUPINF, but not longer;
                 * or it has paths of all lengths > DUPINF but not one of
                 * exactly that length.  In either case, we cannot represent
                 * the possible path lengths from s correctly, so fail.
                 */
                result = false;
                break;
            }
            /* Merge knowledge of these path lengths into what we have */
            for (i = 0; i < DUPINF; i++)
                haspath[i + 1] |= nexthaspath[i];
            /* Infinity + 1 is still infinity */
            haspath[DUPINF + 1] |= nexthaspath[DUPINF + 1];
        }
    }
 
    if (result && foundloop)
    {
        /*
         * If there is a length-1 loop at this state, then find the shortest
         * known path length to the end.  The loop means that every larger
         * path length is possible, too.  (It doesn't matter whether any of
         * the longer lengths were already known possible.)
         */
        int         i;
 
        for (i = 0; i <= DUPINF; i++)
        {
            if (haspath[i])
                break;
        }
        for (i++; i <= DUPINF + 1; i++)
            haspath[i] = true;
    }
 
    /* Report out the completed path length map */
    assert(s->no < nfa->nstates);
    assert(haspaths[s->no] == NULL);
    haspaths[s->no] = haspath;
 
    /* Mark state no longer busy */
    s->tmp = NULL;
 
    return result;
}

References a, assert, checkmatchall_recurse(), DUPINF, fb(), i, INTERRUPT, MALLOC, state::no, nfa::nstates, state::outs, nfa::post, RAINBOW, vars::re, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by checkmatchall(), and checkmatchall_recurse().

cleanup()

static void cleanup ( struct nfa *  nfa )

static

Definition at line 2964 of file regc_nfa.c.

{
    struct state *s;
    struct state *nexts;
    int         n;
 
    if (NISERR())
        return;
 
    /* clear out unreachable or dead-end states */
    /* use pre to mark reachable, then post to mark can-reach-post */
    markreachable(nfa, nfa->pre, (struct state *) NULL, nfa->pre);
    markcanreach(nfa, nfa->post, nfa->pre, nfa->post);
    for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
    {
        nexts = s->next;
        if (s->tmp != nfa->post && !s->flag)
            dropstate(nfa, s);
    }
    assert(NISERR() || nfa->post->nins == 0 || nfa->post->tmp == nfa->post);
    cleartraverse(nfa, nfa->pre);
    assert(NISERR() || nfa->post->nins == 0 || nfa->post->tmp == NULL);
    /* the nins==0 (final unreachable) case will be caught later */
 
    /* renumber surviving states */
    n = 0;
    for (s = nfa->states; s != NULL; s = s->next)
        s->no = n++;
    nfa->nstates = n;
}

References assert, cleartraverse(), dropstate(), fb(), state::flag, markcanreach(), markreachable(), state::next, state::nins, NISERR, state::no, nfa::nstates, nfa::post, nfa::pre, nfa::states, and state::tmp.

cleartraverse()

static void cleartraverse ( struct nfa *  nfa, struct state *  s  )

static

Definition at line 1488 of file regc_nfa.c.

{
    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 (s->tmp == NULL)
        return;
    s->tmp = NULL;
 
    for (a = s->outs; a != NULL; a = a->outchain)
        cleartraverse(nfa, a->to);
}

References a, cleartraverse(), fb(), NERR, state::outs, vars::re, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by cleanup(), cleartraverse(), dupnfa(), and removeconstraints().

cloneouts()

static void cloneouts ( struct nfa *  nfa, struct state *  old, struct state *  from, struct state *  to, int  type  )

static

Definition at line 1256 of file regc_nfa.c.

{
    struct arc *a;
 
    assert(old != from);
    assert(type == AHEAD || type == BEHIND);
 
    for (a = old->outs; a != NULL; a = a->outchain)
    {
        assert(a->type == PLAIN);
        newarc(nfa, type, a->co, from, to);
    }
}

References a, AHEAD, assert, BEHIND, fb(), arc::from, newarc(), PLAIN, arc::to, and type.

clonesuccessorstates()

static void clonesuccessorstates ( struct nfa *  nfa, struct state *  ssource, struct state *  sclone, struct state *  spredecessor, struct arc *  refarc, char *  curdonemap, char *  outerdonemap, int  nstates  )

static

Definition at line 2704 of file regc_nfa.c.

{
    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);
    }
}

References a, a2, assert, clonesuccessorstates(), arc::co, cparc(), dropstate(), fb(), FREE, arc::from, hasconstraintout(), state::ins, isconstraintarc(), MALLOC, NERR, newstate(), state::nins, NISERR, vars::re, REG_ESPACE, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, arc::type, and nfa::v.

Referenced by breakconstraintloop(), and clonesuccessorstates().

combine()

static int combine ( struct nfa *  nfa, struct arc *  con, struct arc *  a  )

static

Definition at line 1987 of file regc_nfa.c.

{
#define  CA(ct,at)   (((ct)<<CHAR_BIT) | (at))
 
    switch (CA(con->type, a->type))
    {
        case CA('^', PLAIN):    /* newlines are handled separately */
        case CA('$', PLAIN):
            return INCOMPATIBLE;
            break;
        case CA(AHEAD, PLAIN):  /* color constraints meet colors */
        case CA(BEHIND, PLAIN):
            if (con->co == a->co)
                return SATISFIED;
            if (con->co == RAINBOW)
            {
                /* con is satisfied unless arc's color is a pseudocolor */
                if (!(nfa->cm->cd[a->co].flags & PSEUDO))
                    return SATISFIED;
            }
            else if (a->co == RAINBOW)
            {
                /* con is incompatible if it's for a pseudocolor */
                /* (this is hypothetical; we make no such constraints today) */
                if (nfa->cm->cd[con->co].flags & PSEUDO)
                    return INCOMPATIBLE;
                /* otherwise, constraint constrains arc to be only its color */
                return REPLACEARC;
            }
            return INCOMPATIBLE;
            break;
        case CA('^', '^'):      /* collision, similar constraints */
        case CA('$', '$'):
            if (con->co == a->co)   /* true duplication */
                return SATISFIED;
            return INCOMPATIBLE;
            break;
        case CA(AHEAD, AHEAD):  /* collision, similar constraints */
        case CA(BEHIND, BEHIND):
            if (con->co == a->co)   /* true duplication */
                return SATISFIED;
            if (con->co == RAINBOW)
            {
                /* con is satisfied unless arc's color is a pseudocolor */
                if (!(nfa->cm->cd[a->co].flags & PSEUDO))
                    return SATISFIED;
            }
            else if (a->co == RAINBOW)
            {
                /* con is incompatible if it's for a pseudocolor */
                /* (this is hypothetical; we make no such constraints today) */
                if (nfa->cm->cd[con->co].flags & PSEUDO)
                    return INCOMPATIBLE;
                /* otherwise, constraint constrains arc to be only its color */
                return REPLACEARC;
            }
            return INCOMPATIBLE;
            break;
        case CA('^', BEHIND):   /* collision, dissimilar constraints */
        case CA(BEHIND, '^'):
        case CA('$', AHEAD):
        case CA(AHEAD, '$'):
            return INCOMPATIBLE;
            break;
        case CA('^', '$'):      /* constraints passing each other */
        case CA('^', AHEAD):
        case CA(BEHIND, '$'):
        case CA(BEHIND, AHEAD):
        case CA('$', '^'):
        case CA('$', BEHIND):
        case CA(AHEAD, '^'):
        case CA(AHEAD, BEHIND):
        case CA('^', LACON):
        case CA(BEHIND, LACON):
        case CA('$', LACON):
        case CA(AHEAD, LACON):
            return COMPATIBLE;
            break;
    }
    assert(NOTREACHED);
    return INCOMPATIBLE;        /* for benefit of blind compilers */
}

References a, AHEAD, assert, BEHIND, CA, colormap::cd, nfa::cm, arc::co, COMPATIBLE, colordesc::flags, INCOMPATIBLE, LACON, NOTREACHED, PLAIN, PSEUDO, RAINBOW, REPLACEARC, SATISFIED, and arc::type.

Referenced by pull(), and push().

compact()

static void compact ( struct nfa *  nfa, struct cnfa *  cnfa  )

static

Definition at line 3514 of file regc_nfa.c.

{
    struct state *s;
    struct arc *a;
    size_t      nstates;
    size_t      narcs;
    struct carc *ca;
    struct carc *first;
 
    assert(!NISERR());
 
    nstates = 0;
    narcs = 0;
    for (s = nfa->states; s != NULL; s = s->next)
    {
        nstates++;
        narcs += s->nouts + 1;  /* need one extra for endmarker */
    }
 
    cnfa->stflags = (char *) MALLOC(nstates * sizeof(char));
    cnfa->states = (struct carc **) MALLOC(nstates * sizeof(struct carc *));
    cnfa->arcs = (struct carc *) MALLOC(narcs * sizeof(struct carc));
    if (cnfa->stflags == NULL || cnfa->states == NULL || cnfa->arcs == NULL)
    {
        if (cnfa->stflags != NULL)
            FREE(cnfa->stflags);
        if (cnfa->states != NULL)
            FREE(cnfa->states);
        if (cnfa->arcs != NULL)
            FREE(cnfa->arcs);
        NERR(REG_ESPACE);
        return;
    }
    cnfa->nstates = nstates;
    cnfa->pre = nfa->pre->no;
    cnfa->post = nfa->post->no;
    cnfa->bos[0] = nfa->bos[0];
    cnfa->bos[1] = nfa->bos[1];
    cnfa->eos[0] = nfa->eos[0];
    cnfa->eos[1] = nfa->eos[1];
    cnfa->ncolors = maxcolor(nfa->cm) + 1;
    cnfa->flags = nfa->flags;
    cnfa->minmatchall = nfa->minmatchall;
    cnfa->maxmatchall = nfa->maxmatchall;
 
    ca = cnfa->arcs;
    for (s = nfa->states; s != NULL; s = s->next)
    {
        assert((size_t) s->no < nstates);
        cnfa->stflags[s->no] = 0;
        cnfa->states[s->no] = ca;
        first = ca;
        for (a = s->outs; a != NULL; a = a->outchain)
            switch (a->type)
            {
                case PLAIN:
                    ca->co = a->co;
                    ca->to = a->to->no;
                    ca++;
                    break;
                case LACON:
                    assert(s->no != cnfa->pre);
                    assert(a->co >= 0);
                    ca->co = (color) (cnfa->ncolors + a->co);
                    ca->to = a->to->no;
                    ca++;
                    cnfa->flags |= HASLACONS;
                    break;
                default:
                    NERR(REG_ASSERT);
                    return;
            }
        carcsort(first, ca - first);
        ca->co = COLORLESS;
        ca->to = 0;
        ca++;
    }
    assert(ca == &cnfa->arcs[narcs]);
    assert(cnfa->nstates != 0);
 
    /* mark no-progress states */
    for (a = nfa->pre->outs; a != NULL; a = a->outchain)
        cnfa->stflags[a->to->no] = CNFA_NOPROGRESS;
    cnfa->stflags[nfa->pre->no] = CNFA_NOPROGRESS;
}

References a, cnfa::arcs, assert, nfa::bos, cnfa::bos, carcsort(), nfa::cm, CNFA_NOPROGRESS, carc::co, COLORLESS, nfa::eos, cnfa::eos, fb(), nfa::flags, cnfa::flags, FREE, HASLACONS, LACON, MALLOC, maxcolor(), nfa::maxmatchall, cnfa::maxmatchall, nfa::minmatchall, cnfa::minmatchall, cnfa::ncolors, NERR, state::next, NISERR, state::no, state::nouts, cnfa::nstates, state::outs, PLAIN, nfa::post, cnfa::post, nfa::pre, cnfa::pre, REG_ASSERT, REG_ESPACE, nfa::states, cnfa::states, and cnfa::stflags.

copyins()

static void copyins ( struct nfa *  nfa, struct state *  oldState, struct state *  newState  )

static

Definition at line 882 of file regc_nfa.c.

{
    assert(oldState != newState);
    assert(newState->nins == 0);    /* see comment above */
 
    if (newState->nins == 0)
    {
        /* No need for de-duplication */
        struct arc *a;
 
        for (a = oldState->ins; a != NULL; a = a->inchain)
            createarc(nfa, a->type, a->co, a->from, newState);
    }
#ifdef NOT_USED                 /* see comment above */
    else 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.
         */
        INTERRUPT(nfa->v->re);
 
        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);
        }
    }
#endif                          /* NOT_USED */
}

References a, assert, BULK_ARC_OP_USE_SORT, cparc(), createarc(), fb(), arc::inchain, INTERRUPT, NISERR, NOTREACHED, vars::re, sortins(), sortins_cmp(), and nfa::v.

Referenced by pull().

copyouts()

static void copyouts ( struct nfa *  nfa, struct state *  oldState, struct state *  newState  )

static

Definition at line 1167 of file regc_nfa.c.

{
    assert(oldState != newState);
    assert(newState->nouts == 0);   /* see comment above */
 
    if (newState->nouts == 0)
    {
        /* No need for de-duplication */
        struct arc *a;
 
        for (a = oldState->outs; a != NULL; a = a->outchain)
            createarc(nfa, a->type, a->co, newState, a->to);
    }
#ifdef NOT_USED                 /* see comment above */
    else 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.
         */
        INTERRUPT(nfa->v->re);
 
        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);
        }
    }
#endif                          /* NOT_USED */
}

References a, assert, BULK_ARC_OP_USE_SORT, cparc(), createarc(), fb(), INTERRUPT, NISERR, NOTREACHED, arc::outchain, vars::re, sortouts(), sortouts_cmp(), and nfa::v.

Referenced by push().

cparc()

static void cparc ( struct nfa *  nfa, struct arc *  oa, struct state *  from, struct state *  to  )

static

Definition at line 608 of file regc_nfa.c.

{
    newarc(nfa, oa->type, oa->co, from, to);
}

References fb(), arc::from, newarc(), and arc::to.

Referenced by breakconstraintloop(), clonesuccessorstates(), copyins(), copyouts(), duptraverse(), moveins(), moveouts(), pull(), and push().

createarc()

static void createarc ( struct nfa *  nfa, int  t, color  co, struct state *  from, struct state *  to  )

static

Definition at line 323 of file regc_nfa.c.

{
    struct arc *a;
 
    a = allocarc(nfa);
    if (NISERR())
        return;
    assert(a != NULL);
 
    a->type = t;
    a->co = 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);
}

References a, allocarc(), assert, nfa::cm, arc::co, colorchain(), COLORED, fb(), arc::from, arc::inchainRev, state::ins, state::nins, NISERR, state::nouts, arc::outchain, arc::outchainRev, state::outs, nfa::parent, and arc::to.

Referenced by copyins(), copyouts(), mergeins(), moveins(), moveouts(), and newarc().

delsub()

static void delsub ( struct nfa *  nfa, struct state *  lp, struct state *  rp  )

static

Definition at line 1281 of file regc_nfa.c.

{
    assert(lp != rp);
 
    rp->tmp = rp;               /* mark end */
 
    deltraverse(nfa, lp, lp);
    if (NISERR())
        return;                 /* asserts might not hold after failure */
    assert(lp->nouts == 0 && rp->nins == 0);    /* did the job */
    assert(lp->no != FREESTATE && rp->no != FREESTATE); /* no more */
 
    rp->tmp = NULL;             /* unmark end */
    lp->tmp = NULL;             /* and begin, marked by deltraverse */
}

References assert, deltraverse(), fb(), FREESTATE, and NISERR.

deltraverse()

static void deltraverse ( struct nfa *  nfa, struct state *  leftend, struct state *  s  )

static

Definition at line 1304 of file regc_nfa.c.

{
    struct arc *a;
    struct state *to;
 
    /* Since this is recursive, it could be driven to stack overflow */
    if (STACK_TOO_DEEP(nfa->v->re))
    {
        NERR(REG_ETOOBIG);
        return;
    }
 
    if (s->nouts == 0)
        return;                 /* nothing to do */
    if (s->tmp != NULL)
        return;                 /* already in progress */
 
    s->tmp = s;                 /* mark as in progress */
 
    while ((a = s->outs) != NULL)
    {
        to = a->to;
        deltraverse(nfa, leftend, to);
        if (NISERR())
            return;             /* asserts might not hold after failure */
        assert(to->nouts == 0 || to->tmp != NULL);
        freearc(nfa, a);
        if (to->nins == 0 && to->tmp == NULL)
        {
            assert(to->nouts == 0);
            freestate(nfa, to);
        }
    }
 
    assert(s->no != FREESTATE); /* we're still here */
    assert(s == leftend || s->nins != 0);   /* and still reachable */
    assert(s->nouts == 0);      /* but have no outarcs */
 
    s->tmp = NULL;              /* we're done here */
}

References a, assert, deltraverse(), fb(), freearc(), FREESTATE, freestate(), NERR, state::nins, NISERR, state::no, state::nouts, state::outs, vars::re, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by delsub(), and deltraverse().

dropstate()

static void dropstate ( struct nfa *  nfa, struct state *  s  )

static

Definition at line 226 of file regc_nfa.c.

{
    struct arc *a;
 
    while ((a = s->ins) != NULL)
        freearc(nfa, a);
    while ((a = s->outs) != NULL)
        freearc(nfa, a);
    freestate(nfa, s);
}

References a, fb(), freearc(), freestate(), state::ins, and state::outs.

Referenced by cleanup(), clonesuccessorstates(), fixconstraintloops(), fixempties(), pullback(), and pushfwd().

dumpnfa()

static void dumpnfa ( struct nfa *  nfa, FILE *  f  )

static

Definition at line 3646 of file regc_nfa.c.

{
#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[0] != COLORLESS)
        fprintf(f, ", eos [%ld]", (long) nfa->eos[0]);
    if (nfa->eos[1] != COLORLESS)
        fprintf(f, ", eol [%ld]", (long) nfa->eos[1]);
    if (nfa->flags & HASLACONS)
        fprintf(f, ", haslacons");
    if (nfa->flags & HASCANTMATCH)
        fprintf(f, ", hascantmatch");
    if (nfa->flags & MATCHALL)
    {
        fprintf(f, ", minmatchall %d", nfa->minmatchall);
        if (nfa->maxmatchall == DUPINF)
            fprintf(f, ", maxmatchall inf");
        else
            fprintf(f, ", maxmatchall %d", nfa->maxmatchall);
    }
    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
}

References nfa::bos, nfa::cm, COLORLESS, DUPINF, nfa::eos, fb(), nfa::flags, fprintf, HASCANTMATCH, HASLACONS, MATCHALL, nfa::maxmatchall, nfa::minmatchall, state::next, state::no, state::nouts, nfa::parent, nfa::post, nfa::pre, and nfa::states.

Referenced by fixconstraintloops(), fixempties(), optimize(), pullback(), and pushfwd().

dupnfa()

static void dupnfa ( struct nfa *  nfa, struct state *  start, struct state *  stop, struct state *  from, struct state *  to  )

static

Definition at line 1355 of file regc_nfa.c.

{
    if (start == stop)
    {
        newarc(nfa, EMPTY, 0, from, to);
        return;
    }
 
    stop->tmp = to;
    duptraverse(nfa, start, from);
    /* done, except for clearing out the tmp pointers */
 
    stop->tmp = NULL;
    cleartraverse(nfa, start);
}

References cleartraverse(), duptraverse(), EMPTY, fb(), newarc(), start, and state::tmp.

duptraverse()

static void duptraverse ( struct nfa *  nfa, struct state *  s, struct state *  stmp  )

static

Definition at line 1379 of file regc_nfa.c.

{
    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 (s->tmp != NULL)
        return;                 /* already done */
 
    s->tmp = (stmp == NULL) ? newstate(nfa) : stmp;
    if (s->tmp == NULL)
    {
        assert(NISERR());
        return;
    }
 
    for (a = s->outs; a != NULL && !NISERR(); a = a->outchain)
    {
        duptraverse(nfa, a->to, (struct state *) NULL);
        if (NISERR())
            break;
        assert(a->to->tmp != NULL);
        cparc(nfa, a, s->tmp, a->to->tmp);
    }
}

References a, assert, cparc(), duptraverse(), fb(), NERR, newstate(), NISERR, state::outs, vars::re, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by dupnfa(), and duptraverse().

emptyreachable()

static struct state * emptyreachable ( struct nfa *  nfa, struct state *  s, struct state *  lastfound, struct arc **  inarcsorig  )

static

Definition at line 2303 of file regc_nfa.c.

{
    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 lastfound;
    }
 
    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;
}

References a, EMPTY, emptyreachable(), fb(), NERR, state::no, vars::re, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by emptyreachable(), and fixempties().

findarc()

static struct arc * findarc ( struct state *  s, int  type, color  co  )

static

Definition at line 592 of file regc_nfa.c.

{
    struct arc *a;
 
    for (a = s->outs; a != NULL; a = a->outchain)
        if (a->type == type && a->co == co)
            return a;
    return NULL;
}

References a, arc::co, fb(), state::outs, and type.

Referenced by colorcomplement().

findconstraintloop()

static int findconstraintloop ( struct nfa *  nfa, struct state *  s  )

static

Definition at line 2469 of file regc_nfa.c.

{
    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;
}

References a, assert, breakconstraintloop(), fb(), findconstraintloop(), isconstraintarc(), NERR, state::outs, vars::re, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by findconstraintloop(), and fixconstraintloops().

fixconstraintloops()

static void fixconstraintloops ( struct nfa *  nfa, FILE *  f  )

static

Definition at line 2370 of file regc_nfa.c.

{
    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);
}

References a, assert, dropstate(), dumpnfa(), fb(), findconstraintloop(), state::flag, freearc(), isconstraintarc(), state::next, state::nins, NISERR, state::nouts, state::outs, nfa::states, and state::tmp.

Referenced by optimize().

fixempties()

static void fixempties ( struct nfa *  nfa, FILE *  f  )

static

Definition at line 2076 of file regc_nfa.c.

{
    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.
     */
    for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
    {
        nexts = s->next;
        if (s->flag || s->nouts != 1)
            continue;
        a = s->outs;
        assert(a != NULL && a->outchain == NULL);
        if (a->type != EMPTY)
            continue;
        if (s != a->to)
            moveins(nfa, s, a->to);
        dropstate(nfa, s);
    }
 
    /*
     * Similarly, get rid of any state with a single EMPTY in-arc, by folding
     * it into its predecessor.
     */
    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);
        if (s->flag || s->nins != 1)
            continue;
        a = s->ins;
        assert(a != NULL && a->inchain == NULL);
        if (a->type != EMPTY)
            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;
 
    /*
     * Now remove all the EMPTY arcs, since we don't need them anymore.
     */
    for (s = nfa->states; s != NULL; s = s->next)
    {
        for (a = s->outs; a != NULL; a = nexta)
        {
            nexta = a->outchain;
            if (a->type == EMPTY)
                freearc(nfa, a);
        }
    }
 
    /*
     * And 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.)
     */
    for (s = nfa->states; s != NULL; s = nexts)
    {
        nexts = s->next;
        if ((s->nins == 0 || s->nouts == 0) && !s->flag)
            dropstate(nfa, s);
    }
 
    if (f != NULL)
        dumpnfa(nfa, f);
}

References a, assert, dropstate(), dumpnfa(), EMPTY, emptyreachable(), fb(), state::flag, FREE, freearc(), hasnonemptyout(), arc::inchain, state::ins, MALLOC, mergeins(), moveins(), moveouts(), NERR, state::next, state::nins, NISERR, state::no, state::nouts, nfa::nstates, state::outs, REG_ESPACE, s2, nfa::states, and state::tmp.

Referenced by optimize().

freearc()

static void freearc ( struct nfa *  nfa, struct arc *  victim  )

static

Definition at line 418 of file regc_nfa.c.

{
    struct state *from = victim->from;
    struct state *to = victim->to;
    struct arc *predecessor;
 
    assert(victim->type != 0);
 
    /* take it off color chain if necessary */
    if (COLORED(victim) && nfa->parent == NULL)
        uncolorchain(nfa->cm, victim);
 
    /* 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 NFA'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 = nfa->freearcs;
    nfa->freearcs = victim;
}

References assert, nfa::cm, COLORED, fb(), nfa::freearcs, arc::from, arc::inchain, state::ins, state::nins, state::nouts, arc::outchain, state::outs, nfa::parent, arc::to, and uncolorchain().

Referenced by breakconstraintloop(), deltraverse(), dropstate(), fixconstraintloops(), fixempties(), moveins(), moveouts(), pull(), pullback(), push(), pushfwd(), removecantmatch(), and removetraverse().

freecnfa()

static void freecnfa ( struct cnfa *  cnfa )

static

Definition at line 3633 of file regc_nfa.c.

{
    assert(!NULLCNFA(*cnfa));   /* not empty already */
    FREE(cnfa->stflags);
    FREE(cnfa->states);
    FREE(cnfa->arcs);
    ZAPCNFA(*cnfa);
}

References cnfa::arcs, assert, FREE, NULLCNFA, cnfa::states, cnfa::stflags, and ZAPCNFA.

freenfa()

static void freenfa ( struct nfa *  nfa )

static

Definition at line 107 of file regc_nfa.c.

{
    struct statebatch *sb;
    struct statebatch *sbnext;
    struct arcbatch *ab;
    struct arcbatch *abnext;
 
    for (sb = nfa->lastsb; sb != NULL; sb = sbnext)
    {
        sbnext = sb->next;
        nfa->v->spaceused -= STATEBATCHSIZE(sb->nstates);
        FREE(sb);
    }
    nfa->lastsb = NULL;
    for (ab = nfa->lastab; ab != NULL; ab = abnext)
    {
        abnext = ab->next;
        nfa->v->spaceused -= ARCBATCHSIZE(ab->narcs);
        FREE(ab);
    }
    nfa->lastab = NULL;
 
    nfa->nstates = -1;
    FREE(nfa);
}

References ARCBATCHSIZE, fb(), FREE, nfa::lastab, nfa::lastsb, arcbatch::next, statebatch::next, nfa::nstates, vars::spaceused, STATEBATCHSIZE, and nfa::v.

Referenced by newnfa().

freestate()

static void freestate ( struct nfa *  nfa, struct state *  s  )

static

Definition at line 242 of file regc_nfa.c.

{
    assert(s != NULL);
    assert(s->nins == 0 && s->nouts == 0);
 
    s->no = FREESTATE;
    s->flag = 0;
    if (s->next != NULL)
        s->next->prev = s->prev;
    else
    {
        assert(s == nfa->slast);
        nfa->slast = s->prev;
    }
    if (s->prev != NULL)
        s->prev->next = s->next;
    else
    {
        assert(s == nfa->states);
        nfa->states = s->next;
    }
    s->prev = NULL;
    s->next = nfa->freestates;  /* don't delete it, put it on the free list */
    nfa->freestates = s;
}

References assert, fb(), state::flag, FREESTATE, nfa::freestates, state::next, state::nins, state::no, state::nouts, state::prev, nfa::slast, and nfa::states.

Referenced by breakconstraintloop(), deltraverse(), and dropstate().

hasconstraintout()

static int hasconstraintout ( struct state *  s )

static

Definition at line 2349 of file regc_nfa.c.

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

References a, fb(), isconstraintarc(), and state::outs.

Referenced by clonesuccessorstates().

hasnonemptyout()

static int hasnonemptyout ( struct state *  s )

static

Definition at line 575 of file regc_nfa.c.

{
    struct arc *a;
 
    for (a = s->outs; a != NULL; a = a->outchain)
    {
        if (a->type != EMPTY)
            return 1;
    }
    return 0;
}

References a, EMPTY, fb(), and state::outs.

Referenced by fixempties().

isconstraintarc()

static int isconstraintarc ( struct arc *  a )

inlinestatic

Definition at line 2331 of file regc_nfa.c.

{
    switch (a->type)
    {
        case '^':
        case '$':
        case BEHIND:
        case AHEAD:
        case LACON:
            return 1;
    }
    return 0;
}

References a, AHEAD, BEHIND, and LACON.

Referenced by breakconstraintloop(), clonesuccessorstates(), findconstraintloop(), fixconstraintloops(), and hasconstraintout().

markcanreach()

static void markcanreach ( struct nfa *  nfa, struct state *  s, struct state *  okay, struct state *  mark  )

static

Definition at line 3025 of file regc_nfa.c.

{
    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 (s->tmp != okay)
        return;
    s->tmp = mark;
 
    for (a = s->ins; a != NULL; a = a->inchain)
        markcanreach(nfa, a->from, okay, mark);
}

References a, fb(), state::ins, markcanreach(), NERR, vars::re, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by cleanup(), and markcanreach().

markreachable()

static void markreachable ( struct nfa *  nfa, struct state *  s, struct state *  okay, struct state *  mark  )

static

Definition at line 2999 of file regc_nfa.c.

{
    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 (s->tmp != okay)
        return;
    s->tmp = mark;
 
    for (a = s->outs; a != NULL; a = a->outchain)
        markreachable(nfa, a->to, okay, mark);
}

References a, fb(), markreachable(), NERR, state::outs, vars::re, REG_ETOOBIG, STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by cleanup(), and markreachable().

mergeins()

static void mergeins ( struct nfa *  nfa, struct state *  s, struct arc **  arcarray, int  arccount  )

static

Definition at line 971 of file regc_nfa.c.

{
    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.
     */
    INTERRUPT(nfa->v->re);
 
    /* 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++;
    }
}

References a, assert, createarc(), fb(), i, state::ins, INTERRUPT, j, NISERR, NOTREACHED, qsort, vars::re, sortins(), sortins_cmp(), and nfa::v.

Referenced by fixempties().

moveins()

static void moveins ( struct nfa *  nfa, struct state *  oldState, struct state *  newState  )

static

Definition at line 778 of file regc_nfa.c.

{
    assert(oldState != newState);
 
    if (newState->nins == 0)
    {
        /* No need for de-duplication */
        struct arc *a;
 
        while ((a = oldState->ins) != NULL)
        {
            createarc(nfa, a->type, a->co, a->from, newState);
            freearc(nfa, a);
        }
    }
    else 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.
         */
        INTERRUPT(nfa->v->re);
 
        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);
}

References a, assert, BULK_ARC_OP_USE_SORT, changearctarget(), cparc(), createarc(), fb(), freearc(), arc::inchain, INTERRUPT, NISERR, NOTREACHED, vars::re, sortins(), sortins_cmp(), and nfa::v.

Referenced by fixempties(), and pull().

moveouts()

static void moveouts ( struct nfa *  nfa, struct state *  oldState, struct state *  newState  )

static

Definition at line 1066 of file regc_nfa.c.

{
    assert(oldState != newState);
 
    if (newState->nouts == 0)
    {
        /* No need for de-duplication */
        struct arc *a;
 
        while ((a = oldState->outs) != NULL)
        {
            createarc(nfa, a->type, a->co, newState, a->to);
            freearc(nfa, a);
        }
    }
    else 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 changearcsource()
         * 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.
         */
        INTERRUPT(nfa->v->re);
 
        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;
 
                    /*
                     * Rather than doing createarc+freearc, we can just unlink
                     * and relink the existing arc struct.
                     */
                    changearcsource(a, newState);
                    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;
            changearcsource(a, newState);
        }
    }
 
    assert(oldState->nouts == 0);
    assert(oldState->outs == NULL);
}

References a, assert, BULK_ARC_OP_USE_SORT, changearcsource(), cparc(), createarc(), fb(), freearc(), INTERRUPT, NISERR, NOTREACHED, arc::outchain, vars::re, sortouts(), sortouts_cmp(), and nfa::v.

Referenced by fixempties(), and push().

newarc()

static void newarc ( struct nfa *  nfa, int  t, color  co, struct state *  from, struct state *  to  )

static

Definition at line 281 of file regc_nfa.c.

{
    struct arc *a;
 
    assert(from != NULL && to != NULL);
 
    /*
     * This is a handy place to check for operation cancel during regex
     * compilation, since no code path will go very long without making a new
     * state or arc.
     */
    INTERRUPT(nfa->v->re);
 
    /* 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);
}

References a, assert, arc::co, createarc(), fb(), arc::from, state::ins, INTERRUPT, state::nins, state::nouts, state::outs, vars::re, arc::to, and nfa::v.

Referenced by cloneouts(), colorcomplement(), cparc(), dupnfa(), newnfa(), okcolors(), pull(), pullback(), push(), pushfwd(), rainbow(), removetraverse(), subcolorcvec(), subcoloronechr(), and subcoloronerow().

newfstate()

static struct state * newfstate ( struct nfa *  nfa, int  flag  )

static

Definition at line 212 of file regc_nfa.c.

{
    struct state *s;
 
    s = newstate(nfa);
    if (s != NULL)
        s->flag = (char) flag;
    return s;
}

References fb(), state::flag, flag(), and newstate().

Referenced by newnfa().

newnfa()

static struct nfa * newnfa ( struct vars *  v, struct colormap *  cm, struct nfa *  parent  )

static

Definition at line 47 of file regc_nfa.c.

{
    struct nfa *nfa;
 
    nfa = (struct nfa *) MALLOC(sizeof(struct nfa));
    if (nfa == NULL)
    {
        ERR(REG_ESPACE);
        return NULL;
    }
 
    /* Make the NFA minimally valid, so freenfa() will behave sanely */
    nfa->states = NULL;
    nfa->slast = NULL;
    nfa->freestates = NULL;
    nfa->freearcs = NULL;
    nfa->lastsb = NULL;
    nfa->lastab = NULL;
    nfa->lastsbused = 0;
    nfa->lastabused = 0;
    nfa->nstates = 0;
    nfa->cm = cm;
    nfa->v = v;
    nfa->bos[0] = nfa->bos[1] = COLORLESS;
    nfa->eos[0] = nfa->eos[1] = COLORLESS;
    nfa->flags = 0;
    nfa->minmatchall = nfa->maxmatchall = -1;
    nfa->parent = parent;       /* Precedes newfstate so parent is valid. */
 
    /* Create required infrastructure */
    nfa->post = newfstate(nfa, '@');    /* number 0 */
    nfa->pre = newfstate(nfa, '>'); /* number 1 */
    nfa->init = newstate(nfa);  /* may become invalid later */
    nfa->final = newstate(nfa);
    if (ISERR())
    {
        freenfa(nfa);
        return NULL;
    }
    rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->pre, nfa->init);
    newarc(nfa, '^', 1, nfa->pre, nfa->init);
    newarc(nfa, '^', 0, nfa->pre, nfa->init);
    rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->final, nfa->post);
    newarc(nfa, '$', 1, nfa->final, nfa->post);
    newarc(nfa, '$', 0, nfa->final, nfa->post);
 
    if (ISERR())
    {
        freenfa(nfa);
        return NULL;
    }
    return nfa;
}

References nfa::bos, nfa::cm, COLORLESS, nfa::eos, ERR, fb(), nfa::final, nfa::flags, nfa::freearcs, freenfa(), nfa::freestates, nfa::init, ISERR, nfa::lastab, nfa::lastabused, nfa::lastsb, nfa::lastsbused, MALLOC, nfa::maxmatchall, nfa::minmatchall, newarc(), newfstate(), newstate(), nfa::nstates, nfa::parent, PLAIN, nfa::post, nfa::pre, rainbow(), REG_ESPACE, nfa::slast, nfa::states, and nfa::v.

newstate()

static struct state * newstate ( struct nfa *  nfa )

static

Definition at line 137 of file regc_nfa.c.

{
    struct state *s;
 
    /*
     * This is a handy place to check for operation cancel during regex
     * compilation, since no code path will go very long without making a new
     * state or arc.
     */
    INTERRUPT(nfa->v->re);
 
    /* first, recycle anything that's on the freelist */
    if (nfa->freestates != NULL)
    {
        s = nfa->freestates;
        nfa->freestates = s->next;
    }
    /* otherwise, is there anything left in the last statebatch? */
    else if (nfa->lastsb != NULL && nfa->lastsbused < nfa->lastsb->nstates)
    {
        s = &nfa->lastsb->s[nfa->lastsbused++];
    }
    /* otherwise, need to allocate a new statebatch */
    else
    {
        struct statebatch *newSb;
        size_t      nstates;
 
        if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE)
        {
            NERR(REG_ETOOBIG);
            return NULL;
        }
        nstates = (nfa->lastsb != NULL) ? nfa->lastsb->nstates * 2 : FIRSTSBSIZE;
        if (nstates > MAXSBSIZE)
            nstates = MAXSBSIZE;
        newSb = (struct statebatch *) MALLOC(STATEBATCHSIZE(nstates));
        if (newSb == NULL)
        {
            NERR(REG_ESPACE);
            return NULL;
        }
        nfa->v->spaceused += STATEBATCHSIZE(nstates);
        newSb->nstates = nstates;
        newSb->next = nfa->lastsb;
        nfa->lastsb = newSb;
        nfa->lastsbused = 1;
        s = &newSb->s[0];
    }
 
    assert(nfa->nstates >= 0);
    s->no = nfa->nstates++;
    s->flag = 0;
    if (nfa->states == NULL)
        nfa->states = s;
    s->nins = 0;
    s->ins = NULL;
    s->nouts = 0;
    s->outs = NULL;
    s->tmp = NULL;
    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;
}

References assert, fb(), FIRSTSBSIZE, state::flag, nfa::freestates, state::ins, INTERRUPT, nfa::lastsb, nfa::lastsbused, MALLOC, MAXSBSIZE, NERR, state::next, state::nins, state::no, state::nouts, statebatch::nstates, nfa::nstates, state::outs, state::prev, vars::re, REG_ESPACE, REG_ETOOBIG, REG_MAX_COMPILE_SPACE, statebatch::s, nfa::slast, vars::spaceused, STATEBATCHSIZE, nfa::states, state::tmp, and nfa::v.

Referenced by breakconstraintloop(), clonesuccessorstates(), duptraverse(), newfstate(), newnfa(), pull(), push(), and SetMatViewPopulatedState().

optimize()

static long optimize ( struct nfa *  nfa, FILE *  f  )

static

Definition at line 1594 of file regc_nfa.c.

{
#ifdef REG_DEBUG
    int         verbose = (f != NULL) ? 1 : 0;
 
    if (verbose)
        fprintf(f, "\ninitial cleanup:\n");
#endif
    /* If we have any CANTMATCH arcs, drop them; but this is uncommon */
    if (nfa->flags & HASCANTMATCH)
    {
        removecantmatch(nfa);
        nfa->flags &= ~HASCANTMATCH;
    }
    cleanup(nfa);               /* may simplify situation */
#ifdef REG_DEBUG
    if (verbose)
        dumpnfa(nfa, f);
    if (verbose)
        fprintf(f, "\nempties:\n");
#endif
    fixempties(nfa, f);         /* get rid of EMPTY arcs */
#ifdef REG_DEBUG
    if (verbose)
        fprintf(f, "\nconstraints:\n");
#endif
    fixconstraintloops(nfa, f); /* get rid of constraint loops */
    pullback(nfa, f);           /* pull back constraints backward */
    pushfwd(nfa, f);            /* push fwd constraints forward */
#ifdef REG_DEBUG
    if (verbose)
        fprintf(f, "\nfinal cleanup:\n");
#endif
    cleanup(nfa);               /* final tidying */
#ifdef REG_DEBUG
    if (verbose)
        dumpnfa(nfa, f);
#endif
    return analyze(nfa);        /* and analysis */
}

References analyze(), cleanup(), dumpnfa(), fb(), fixconstraintloops(), fixempties(), nfa::flags, fprintf, HASCANTMATCH, pullback(), pushfwd(), removecantmatch(), and verbose.

pull()

static int pull ( struct nfa *  nfa, struct arc *  con, struct state **  intermediates  )

static

Definition at line 1720 of file regc_nfa.c.

{
    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(nfa, 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;
            case REPLACEARC:    /* replace arc's color */
                newarc(nfa, a->type, con->co, a->from, 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;
}

References a, assert, arc::co, combine(), COMPATIBLE, copyins(), cparc(), fb(), state::flag, freearc(), arc::from, INCOMPATIBLE, state::ins, moveins(), newarc(), newstate(), state::nins, NISERR, NOTREACHED, state::nouts, state::outs, REPLACEARC, SATISFIED, state::tmp, and arc::to.

Referenced by pullback().

pullback()

static void pullback ( struct nfa *  nfa, FILE *  f  )

static

Definition at line 1640 of file regc_nfa.c.

{
    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;
            }
            /* 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);
        }
    }
}

References a, assert, BEHIND, nfa::bos, dropstate(), dumpnfa(), fb(), state::flag, freearc(), newarc(), state::next, state::nins, NISERR, state::nouts, state::outs, PLAIN, nfa::pre, progress, pull(), nfa::states, and state::tmp.

Referenced by optimize().

push()

static int push ( struct nfa *  nfa, struct arc *  con, struct state **  intermediates  )

static

Definition at line 1891 of file regc_nfa.c.

{
    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(nfa, 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;
            case REPLACEARC:    /* replace arc's color */
                newarc(nfa, a->type, con->co, from, a->to);
                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;
}

References a, assert, arc::co, combine(), COMPATIBLE, copyouts(), cparc(), fb(), state::flag, freearc(), arc::from, INCOMPATIBLE, state::ins, moveouts(), newarc(), newstate(), state::nins, NISERR, NOTREACHED, state::nouts, state::outs, REPLACEARC, SATISFIED, state::tmp, and arc::to.

Referenced by pushfwd().

pushfwd()

static void pushfwd ( struct nfa *  nfa, FILE *  f  )

static

Definition at line 1811 of file regc_nfa.c.

{
    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);
        }
    }
}

References a, AHEAD, assert, dropstate(), dumpnfa(), nfa::eos, fb(), state::flag, freearc(), state::ins, newarc(), state::next, state::nins, NISERR, state::nouts, PLAIN, nfa::post, progress, push(), nfa::states, and state::tmp.

Referenced by optimize().

removecantmatch()

static void removecantmatch ( struct nfa *  nfa )

static

Definition at line 2938 of file regc_nfa.c.

{
    struct state *s;
 
    for (s = nfa->states; s != NULL; s = s->next)
    {
        struct arc *a;
        struct arc *nexta;
 
        for (a = s->outs; a != NULL; a = nexta)
        {
            nexta = a->outchain;
            if (a->type == CANTMATCH)
            {
                freearc(nfa, a);
                if (NISERR())
                    return;
            }
        }
    }
}

References a, CANTMATCH, fb(), freearc(), state::next, NISERR, arc::outchain, state::outs, and nfa::states.

Referenced by optimize().

removeconstraints()

static void removeconstraints ( struct nfa *  nfa, struct state *  start, struct state *  stop  )

static

Definition at line 1419 of file regc_nfa.c.

{
    if (start == stop)
        return;
 
    stop->tmp = stop;
    removetraverse(nfa, start);
    /* done, except for clearing out the tmp pointers */
 
    stop->tmp = NULL;
    cleartraverse(nfa, start);
}

References cleartraverse(), fb(), removetraverse(), start, and state::tmp.

removetraverse()

static void removetraverse ( struct nfa *  nfa, struct state *  s  )

static

Definition at line 1438 of file regc_nfa.c.

{
    struct arc *a;
    struct arc *oa;
 
    /* Since this is recursive, it could be driven to stack overflow */
    if (STACK_TOO_DEEP(nfa->v->re))
    {
        NERR(REG_ETOOBIG);
        return;
    }
 
    if (s->tmp != NULL)
        return;                 /* already done */
 
    s->tmp = s;
    for (a = s->outs; a != NULL && !NISERR(); a = oa)
    {
        removetraverse(nfa, a->to);
        if (NISERR())
            break;
        oa = a->outchain;
        switch (a->type)
        {
            case PLAIN:
            case EMPTY:
            case CANTMATCH:
                /* nothing to do */
                break;
            case AHEAD:
            case BEHIND:
            case '^':
            case '$':
            case LACON:
                /* replace it */
                newarc(nfa, EMPTY, 0, s, a->to);
                freearc(nfa, a);
                break;
            default:
                NERR(REG_ASSERT);
                break;
        }
    }
}

References a, AHEAD, BEHIND, CANTMATCH, EMPTY, fb(), freearc(), LACON, NERR, newarc(), NISERR, state::outs, PLAIN, vars::re, REG_ASSERT, REG_ETOOBIG, removetraverse(), STACK_TOO_DEEP, state::tmp, and nfa::v.

Referenced by removeconstraints(), and removetraverse().

single_color_transition()

static struct state * single_color_transition ( struct state *  s1, struct state *  s2  )

static

Definition at line 1525 of file regc_nfa.c.

{
    struct arc *a;
 
    /* Ignore leading EMPTY arc, if any */
    if (s1->nouts == 1 && s1->outs->type == EMPTY)
        s1 = s1->outs->to;
    /* Likewise for any trailing EMPTY arc */
    if (s2->nins == 1 && s2->ins->type == EMPTY)
        s2 = s2->ins->from;
    /* Perhaps we could have a single-state loop in between, if so reject */
    if (s1 == s2)
        return NULL;
    /* s1 must have at least one outarc... */
    if (s1->outs == NULL)
        return NULL;
    /* ... and they must all be PLAIN arcs to s2 */
    for (a = s1->outs; a != NULL; a = a->outchain)
    {
        if (a->type != PLAIN || a->to != s2)
            return NULL;
    }
    /* OK, return s1 as the possessor of the relevant outarcs */
    return s1;
}

References a, EMPTY, fb(), arc::from, state::ins, PLAIN, s1, s2, and arc::to.

sortins()

static void sortins ( struct nfa *  nfa, struct state *  s  )

static

Definition at line 620 of file regc_nfa.c.

{
    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);
}

References a, assert, fb(), FREE, i, arc::inchain, arc::inchainRev, state::ins, MALLOC, NERR, state::nins, qsort, REG_ESPACE, and sortins_cmp().

Referenced by copyins(), mergeins(), and moveins().

sortins_cmp()

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

static

Definition at line 662 of file regc_nfa.c.

{
    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;
}

References a, b, and fb().

Referenced by copyins(), mergeins(), moveins(), and sortins().

sortouts()

static void sortouts ( struct nfa *  nfa, struct state *  s  )

static

Definition at line 687 of file regc_nfa.c.

{
    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);
}

References a, assert, fb(), FREE, i, MALLOC, NERR, state::nouts, arc::outchain, arc::outchainRev, state::outs, qsort, REG_ESPACE, and sortouts_cmp().

Referenced by copyouts(), and moveouts().

sortouts_cmp()

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

static

Definition at line 729 of file regc_nfa.c.

{
    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;
}

References a, b, and fb().

Referenced by copyouts(), moveouts(), and sortouts().

specialcolors()

static void specialcolors ( struct nfa *  nfa )

static

Definition at line 1555 of file regc_nfa.c.

{
    /* false colors for BOS, BOL, EOS, EOL */
    if (nfa->parent == NULL)
    {
        nfa->bos[0] = pseudocolor(nfa->cm);
        nfa->bos[1] = pseudocolor(nfa->cm);
        nfa->eos[0] = pseudocolor(nfa->cm);
        nfa->eos[1] = pseudocolor(nfa->cm);
    }
    else
    {
        assert(nfa->parent->bos[0] != COLORLESS);
        nfa->bos[0] = nfa->parent->bos[0];
        assert(nfa->parent->bos[1] != COLORLESS);
        nfa->bos[1] = nfa->parent->bos[1];
        assert(nfa->parent->eos[0] != COLORLESS);
        nfa->eos[0] = nfa->parent->eos[0];
        assert(nfa->parent->eos[1] != COLORLESS);
        nfa->eos[1] = nfa->parent->eos[1];
    }
}

References assert, nfa::bos, nfa::cm, COLORLESS, nfa::eos, fb(), nfa::parent, and pseudocolor().