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-rw-r--r--generic/rege_dfa.c1351
1 files changed, 677 insertions, 674 deletions
diff --git a/generic/rege_dfa.c b/generic/rege_dfa.c
index a13dfa4..24ff2db 100644
--- a/generic/rege_dfa.c
+++ b/generic/rege_dfa.c
@@ -1,674 +1,677 @@
-/*
- * DFA routines
- * This file is #included by regexec.c.
- *
- * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
- *
- * Development of this software was funded, in part, by Cray Research Inc.,
- * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
- * Corporation, none of whom are responsible for the results. The author
- * thanks all of them.
- *
- * Redistribution and use in source and binary forms -- with or without
- * modification -- are permitted for any purpose, provided that
- * redistributions in source form retain this entire copyright notice and
- * indicate the origin and nature of any modifications.
- *
- * I'd appreciate being given credit for this package in the documentation
- * of software which uses it, but that is not a requirement.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
- * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
- * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-/*
- - longest - longest-preferred matching engine
- ^ static chr *longest(struct vars *, struct dfa *, chr *, chr *, int *);
- */
-static chr * /* endpoint, or NULL */
-longest(v, d, start, stop, hitstopp)
-struct vars *v; /* used only for debug and exec flags */
-struct dfa *d;
-chr *start; /* where the match should start */
-chr *stop; /* match must end at or before here */
-int *hitstopp; /* record whether hit v->stop, if non-NULL */
-{
- chr *cp;
- chr *realstop = (stop == v->stop) ? stop : stop + 1;
- color co;
- struct sset *css;
- struct sset *ss;
- chr *post;
- int i;
- struct colormap *cm = d->cm;
-
- /* initialize */
- css = initialize(v, d, start);
- cp = start;
- if (hitstopp != NULL)
- *hitstopp = 0;
-
- /* startup */
- FDEBUG(("+++ startup +++\n"));
- if (cp == v->start) {
- co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
- FDEBUG(("color %ld\n", (long)co));
- } else {
- co = GETCOLOR(cm, *(cp - 1));
- FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
- }
- css = miss(v, d, css, co, cp, start);
- if (css == NULL)
- return NULL;
- css->lastseen = cp;
-
- /* main loop */
- if (v->eflags&REG_FTRACE)
- while (cp < realstop) {
- FDEBUG(("+++ at c%d +++\n", css - d->ssets));
- co = GETCOLOR(cm, *cp);
- FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
- ss = css->outs[co];
- if (ss == NULL) {
- ss = miss(v, d, css, co, cp+1, start);
- if (ss == NULL)
- break; /* NOTE BREAK OUT */
- }
- cp++;
- ss->lastseen = cp;
- css = ss;
- }
- else
- while (cp < realstop) {
- co = GETCOLOR(cm, *cp);
- ss = css->outs[co];
- if (ss == NULL) {
- ss = miss(v, d, css, co, cp+1, start);
- if (ss == NULL)
- break; /* NOTE BREAK OUT */
- }
- cp++;
- ss->lastseen = cp;
- css = ss;
- }
-
- /* shutdown */
- FDEBUG(("+++ shutdown at c%d +++\n", css - d->ssets));
- if (cp == v->stop && stop == v->stop) {
- if (hitstopp != NULL)
- *hitstopp = 1;
- co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
- FDEBUG(("color %ld\n", (long)co));
- ss = miss(v, d, css, co, cp, start);
- /* special case: match ended at eol? */
- if (ss != NULL && (ss->flags&POSTSTATE))
- return cp;
- else if (ss != NULL)
- ss->lastseen = cp; /* to be tidy */
- }
-
- /* find last match, if any */
- post = d->lastpost;
- for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
- if ((ss->flags&POSTSTATE) && post != ss->lastseen &&
- (post == NULL || post < ss->lastseen))
- post = ss->lastseen;
- if (post != NULL) /* found one */
- return post - 1;
-
- return NULL;
-}
-
-/*
- - shortest - shortest-preferred matching engine
- ^ static chr *shortest(struct vars *, struct dfa *, chr *, chr *, chr *,
- ^ chr **, int *);
- */
-static chr * /* endpoint, or NULL */
-shortest(v, d, start, min, max, coldp, hitstopp)
-struct vars *v;
-struct dfa *d;
-chr *start; /* where the match should start */
-chr *min; /* match must end at or after here */
-chr *max; /* match must end at or before here */
-chr **coldp; /* store coldstart pointer here, if nonNULL */
-int *hitstopp; /* record whether hit v->stop, if non-NULL */
-{
- chr *cp;
- chr *realmin = (min == v->stop) ? min : min + 1;
- chr *realmax = (max == v->stop) ? max : max + 1;
- color co;
- struct sset *css;
- struct sset *ss;
- struct colormap *cm = d->cm;
-
- /* initialize */
- css = initialize(v, d, start);
- cp = start;
- if (hitstopp != NULL)
- *hitstopp = 0;
-
- /* startup */
- FDEBUG(("--- startup ---\n"));
- if (cp == v->start) {
- co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
- FDEBUG(("color %ld\n", (long)co));
- } else {
- co = GETCOLOR(cm, *(cp - 1));
- FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
- }
- css = miss(v, d, css, co, cp, start);
- if (css == NULL)
- return NULL;
- css->lastseen = cp;
- ss = css;
-
- /* main loop */
- if (v->eflags&REG_FTRACE)
- while (cp < realmax) {
- FDEBUG(("--- at c%d ---\n", css - d->ssets));
- co = GETCOLOR(cm, *cp);
- FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
- ss = css->outs[co];
- if (ss == NULL) {
- ss = miss(v, d, css, co, cp+1, start);
- if (ss == NULL)
- break; /* NOTE BREAK OUT */
- }
- cp++;
- ss->lastseen = cp;
- css = ss;
- if ((ss->flags&POSTSTATE) && cp >= realmin)
- break; /* NOTE BREAK OUT */
- }
- else
- while (cp < realmax) {
- co = GETCOLOR(cm, *cp);
- ss = css->outs[co];
- if (ss == NULL) {
- ss = miss(v, d, css, co, cp+1, start);
- if (ss == NULL)
- break; /* NOTE BREAK OUT */
- }
- cp++;
- ss->lastseen = cp;
- css = ss;
- if ((ss->flags&POSTSTATE) && cp >= realmin)
- break; /* NOTE BREAK OUT */
- }
-
- if (ss == NULL)
- return NULL;
-
- if (coldp != NULL) /* report last no-progress state set, if any */
- *coldp = lastcold(v, d);
-
- if ((ss->flags&POSTSTATE) && cp > min) {
- assert(cp >= realmin);
- cp--;
- } else if (cp == v->stop && max == v->stop) {
- co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
- FDEBUG(("color %ld\n", (long)co));
- ss = miss(v, d, css, co, cp, start);
- /* match might have ended at eol */
- if ((ss == NULL || !(ss->flags&POSTSTATE)) && hitstopp != NULL)
- *hitstopp = 1;
- }
-
- if (ss == NULL || !(ss->flags&POSTSTATE))
- return NULL;
-
- return cp;
-}
-
-/*
- - lastcold - determine last point at which no progress had been made
- ^ static chr *lastcold(struct vars *, struct dfa *);
- */
-static chr * /* endpoint, or NULL */
-lastcold(v, d)
-struct vars *v;
-struct dfa *d;
-{
- struct sset *ss;
- chr *nopr;
- int i;
-
- nopr = d->lastnopr;
- if (nopr == NULL)
- nopr = v->start;
- for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
- if ((ss->flags&NOPROGRESS) && nopr < ss->lastseen)
- nopr = ss->lastseen;
- return nopr;
-}
-
-/*
- - newdfa - set up a fresh DFA
- ^ static struct dfa *newdfa(struct vars *, struct cnfa *,
- ^ struct colormap *, struct smalldfa *);
- */
-static struct dfa *
-newdfa(v, cnfa, cm, small)
-struct vars *v;
-struct cnfa *cnfa;
-struct colormap *cm;
-struct smalldfa *small; /* preallocated space, may be NULL */
-{
- struct dfa *d;
- size_t nss = cnfa->nstates * 2;
- int wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
- struct smalldfa *smallwas = small;
-
- assert(cnfa != NULL && cnfa->nstates != 0);
-
- if (nss <= FEWSTATES && cnfa->ncolors <= FEWCOLORS) {
- assert(wordsper == 1);
- if (small == NULL) {
- small = (struct smalldfa *)MALLOC(
- sizeof(struct smalldfa));
- if (small == NULL) {
- ERR(REG_ESPACE);
- return NULL;
- }
- }
- d = &small->dfa;
- d->ssets = small->ssets;
- d->statesarea = small->statesarea;
- d->work = &d->statesarea[nss];
- d->outsarea = small->outsarea;
- d->incarea = small->incarea;
- d->cptsmalloced = 0;
- d->mallocarea = (smallwas == NULL) ? (char *)small : NULL;
- } else {
- d = (struct dfa *)MALLOC(sizeof(struct dfa));
- if (d == NULL) {
- ERR(REG_ESPACE);
- return NULL;
- }
- d->ssets = (struct sset *)MALLOC(nss * sizeof(struct sset));
- d->statesarea = (unsigned *)MALLOC((nss+WORK) * wordsper *
- sizeof(unsigned));
- d->work = &d->statesarea[nss * wordsper];
- d->outsarea = (struct sset **)MALLOC(nss * cnfa->ncolors *
- sizeof(struct sset *));
- d->incarea = (struct arcp *)MALLOC(nss * cnfa->ncolors *
- sizeof(struct arcp));
- d->cptsmalloced = 1;
- d->mallocarea = (char *)d;
- if (d->ssets == NULL || d->statesarea == NULL ||
- d->outsarea == NULL || d->incarea == NULL) {
- freedfa(d);
- ERR(REG_ESPACE);
- return NULL;
- }
- }
-
- d->nssets = (v->eflags&REG_SMALL) ? 7 : nss;
- d->nssused = 0;
- d->nstates = cnfa->nstates;
- d->ncolors = cnfa->ncolors;
- d->wordsper = wordsper;
- d->cnfa = cnfa;
- d->cm = cm;
- d->lastpost = NULL;
- d->lastnopr = NULL;
- d->search = d->ssets;
-
- /* initialization of sset fields is done as needed */
-
- return d;
-}
-
-/*
- - freedfa - free a DFA
- ^ static VOID freedfa(struct dfa *);
- */
-static VOID
-freedfa(d)
-struct dfa *d;
-{
- if (d->cptsmalloced) {
- if (d->ssets != NULL)
- FREE(d->ssets);
- if (d->statesarea != NULL)
- FREE(d->statesarea);
- if (d->outsarea != NULL)
- FREE(d->outsarea);
- if (d->incarea != NULL)
- FREE(d->incarea);
- }
-
- if (d->mallocarea != NULL)
- FREE(d->mallocarea);
-}
-
-/*
- - hash - construct a hash code for a bitvector
- * There are probably better ways, but they're more expensive.
- ^ static unsigned hash(unsigned *, int);
- */
-static unsigned
-hash(uv, n)
-unsigned *uv;
-int n;
-{
- int i;
- unsigned h;
-
- h = 0;
- for (i = 0; i < n; i++)
- h ^= uv[i];
- return h;
-}
-
-/*
- - initialize - hand-craft a cache entry for startup, otherwise get ready
- ^ static struct sset *initialize(struct vars *, struct dfa *, chr *);
- */
-static struct sset *
-initialize(v, d, start)
-struct vars *v; /* used only for debug flags */
-struct dfa *d;
-chr *start;
-{
- struct sset *ss;
- int i;
-
- /* is previous one still there? */
- if (d->nssused > 0 && (d->ssets[0].flags&STARTER))
- ss = &d->ssets[0];
- else { /* no, must (re)build it */
- ss = getvacant(v, d, start, start);
- for (i = 0; i < d->wordsper; i++)
- ss->states[i] = 0;
- BSET(ss->states, d->cnfa->pre);
- ss->hash = HASH(ss->states, d->wordsper);
- assert(d->cnfa->pre != d->cnfa->post);
- ss->flags = STARTER|LOCKED|NOPROGRESS;
- /* lastseen dealt with below */
- }
-
- for (i = 0; i < d->nssused; i++)
- d->ssets[i].lastseen = NULL;
- ss->lastseen = start; /* maybe untrue, but harmless */
- d->lastpost = NULL;
- d->lastnopr = NULL;
- return ss;
-}
-
-/*
- - miss - handle a cache miss
- ^ static struct sset *miss(struct vars *, struct dfa *, struct sset *,
- ^ pcolor, chr *, chr *);
- */
-static struct sset * /* NULL if goes to empty set */
-miss(v, d, css, co, cp, start)
-struct vars *v; /* used only for debug flags */
-struct dfa *d;
-struct sset *css;
-pcolor co;
-chr *cp; /* next chr */
-chr *start; /* where the attempt got started */
-{
- struct cnfa *cnfa = d->cnfa;
- int i;
- unsigned h;
- struct carc *ca;
- struct sset *p;
- int ispost;
- int noprogress;
- int gotstate;
- int dolacons;
- int didlacons;
-
- /* for convenience, we can be called even if it might not be a miss */
- if (css->outs[co] != NULL) {
- FDEBUG(("hit\n"));
- return css->outs[co];
- }
- FDEBUG(("miss\n"));
-
- /* first, what set of states would we end up in? */
- for (i = 0; i < d->wordsper; i++)
- d->work[i] = 0;
- ispost = 0;
- noprogress = 1;
- gotstate = 0;
- for (i = 0; i < d->nstates; i++)
- if (ISBSET(css->states, i))
- for (ca = cnfa->states[i]+1; ca->co != COLORLESS; ca++)
- if (ca->co == co) {
- BSET(d->work, ca->to);
- gotstate = 1;
- if (ca->to == cnfa->post)
- ispost = 1;
- if (!cnfa->states[ca->to]->co)
- noprogress = 0;
- FDEBUG(("%d -> %d\n", i, ca->to));
- }
- dolacons = (gotstate) ? (cnfa->flags&HASLACONS) : 0;
- didlacons = 0;
- while (dolacons) { /* transitive closure */
- dolacons = 0;
- for (i = 0; i < d->nstates; i++)
- if (ISBSET(d->work, i))
- for (ca = cnfa->states[i]+1; ca->co != COLORLESS;
- ca++)
- if (ca->co > cnfa->ncolors &&
- !ISBSET(d->work, ca->to) &&
- lacon(v, cnfa, cp,
- ca->co)) {
- BSET(d->work, ca->to);
- dolacons = 1;
- didlacons = 1;
- if (ca->to == cnfa->post)
- ispost = 1;
- if (!cnfa->states[ca->to]->co)
- noprogress = 0;
- FDEBUG(("%d :> %d\n",i,ca->to));
- }
- }
- if (!gotstate)
- return NULL;
- h = HASH(d->work, d->wordsper);
-
- /* next, is that in the cache? */
- for (p = d->ssets, i = d->nssused; i > 0; p++, i--)
- if (HIT(h, d->work, p, d->wordsper)) {
- FDEBUG(("cached c%d\n", p - d->ssets));
- break; /* NOTE BREAK OUT */
- }
- if (i == 0) { /* nope, need a new cache entry */
- p = getvacant(v, d, cp, start);
- assert(p != css);
- for (i = 0; i < d->wordsper; i++)
- p->states[i] = d->work[i];
- p->hash = h;
- p->flags = (ispost) ? POSTSTATE : 0;
- if (noprogress)
- p->flags |= NOPROGRESS;
- /* lastseen to be dealt with by caller */
- }
-
- if (!didlacons) { /* lookahead conds. always cache miss */
- css->outs[co] = p;
- css->inchain[co] = p->ins;
- p->ins.ss = css;
- p->ins.co = (color)co;
- }
- return p;
-}
-
-/*
- - lacon - lookahead-constraint checker for miss()
- ^ static int lacon(struct vars *, struct cnfa *, chr *, pcolor);
- */
-static int /* predicate: constraint satisfied? */
-lacon(v, pcnfa, cp, co)
-struct vars *v;
-struct cnfa *pcnfa; /* parent cnfa */
-chr *cp;
-pcolor co; /* "color" of the lookahead constraint */
-{
- int n;
- struct subre *sub;
- struct dfa *d;
- struct smalldfa sd;
- chr *end;
-
- n = co - pcnfa->ncolors;
- assert(n < v->g->nlacons && v->g->lacons != NULL);
- FDEBUG(("=== testing lacon %d\n", n));
- sub = &v->g->lacons[n];
- d = newdfa(v, &sub->cnfa, &v->g->cmap, &sd);
- if (d == NULL) {
- ERR(REG_ESPACE);
- return 0;
- }
- end = longest(v, d, cp, v->stop, (int *)NULL);
- freedfa(d);
- FDEBUG(("=== lacon %d match %d\n", n, (end != NULL)));
- return (sub->subno) ? (end != NULL) : (end == NULL);
-}
-
-/*
- - getvacant - get a vacant state set
- * This routine clears out the inarcs and outarcs, but does not otherwise
- * clear the innards of the state set -- that's up to the caller.
- ^ static struct sset *getvacant(struct vars *, struct dfa *, chr *, chr *);
- */
-static struct sset *
-getvacant(v, d, cp, start)
-struct vars *v; /* used only for debug flags */
-struct dfa *d;
-chr *cp;
-chr *start;
-{
- int i;
- struct sset *ss;
- struct sset *p;
- struct arcp ap;
- struct arcp lastap;
- color co;
-
- ss = pickss(v, d, cp, start);
- assert(!(ss->flags&LOCKED));
-
- /* clear out its inarcs, including self-referential ones */
- ap = ss->ins;
- while ((p = ap.ss) != NULL) {
- co = ap.co;
- FDEBUG(("zapping c%d's %ld outarc\n", p - d->ssets, (long)co));
- p->outs[co] = NULL;
- ap = p->inchain[co];
- p->inchain[co].ss = NULL; /* paranoia */
- }
- ss->ins.ss = NULL;
-
- /* take it off the inarc chains of the ssets reached by its outarcs */
- for (i = 0; i < d->ncolors; i++) {
- p = ss->outs[i];
- assert(p != ss); /* not self-referential */
- if (p == NULL)
- continue; /* NOTE CONTINUE */
- FDEBUG(("del outarc %d from c%d's in chn\n", i, p - d->ssets));
- if (p->ins.ss == ss && p->ins.co == i)
- p->ins = ss->inchain[i];
- else {
- assert(p->ins.ss != NULL);
- for (ap = p->ins; ap.ss != NULL &&
- !(ap.ss == ss && ap.co == i);
- ap = ap.ss->inchain[ap.co])
- lastap = ap;
- assert(ap.ss != NULL);
- lastap.ss->inchain[lastap.co] = ss->inchain[i];
- }
- ss->outs[i] = NULL;
- ss->inchain[i].ss = NULL;
- }
-
- /* if ss was a success state, may need to remember location */
- if ((ss->flags&POSTSTATE) && ss->lastseen != d->lastpost &&
- (d->lastpost == NULL || d->lastpost < ss->lastseen))
- d->lastpost = ss->lastseen;
-
- /* likewise for a no-progress state */
- if ((ss->flags&NOPROGRESS) && ss->lastseen != d->lastnopr &&
- (d->lastnopr == NULL || d->lastnopr < ss->lastseen))
- d->lastnopr = ss->lastseen;
-
- return ss;
-}
-
-/*
- - pickss - pick the next stateset to be used
- ^ static struct sset *pickss(struct vars *, struct dfa *, chr *, chr *);
- */
-static struct sset *
-pickss(v, d, cp, start)
-struct vars *v; /* used only for debug flags */
-struct dfa *d;
-chr *cp;
-chr *start;
-{
- int i;
- struct sset *ss;
- struct sset *end;
- chr *ancient;
-
- /* shortcut for cases where cache isn't full */
- if (d->nssused < d->nssets) {
- i = d->nssused;
- d->nssused++;
- ss = &d->ssets[i];
- FDEBUG(("new c%d\n", i));
- /* set up innards */
- ss->states = &d->statesarea[i * d->wordsper];
- ss->flags = 0;
- ss->ins.ss = NULL;
- ss->ins.co = WHITE; /* give it some value */
- ss->outs = &d->outsarea[i * d->ncolors];
- ss->inchain = &d->incarea[i * d->ncolors];
- for (i = 0; i < d->ncolors; i++) {
- ss->outs[i] = NULL;
- ss->inchain[i].ss = NULL;
- }
- return ss;
- }
-
- /* look for oldest, or old enough anyway */
- if (cp - start > d->nssets*2/3) /* oldest 33% are expendable */
- ancient = cp - d->nssets*2/3;
- else
- ancient = start;
- for (ss = d->search, end = &d->ssets[d->nssets]; ss < end; ss++)
- if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
- !(ss->flags&LOCKED)) {
- d->search = ss + 1;
- FDEBUG(("replacing c%d\n", ss - d->ssets));
- return ss;
- }
- for (ss = d->ssets, end = d->search; ss < end; ss++)
- if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
- !(ss->flags&LOCKED)) {
- d->search = ss + 1;
- FDEBUG(("replacing c%d\n", ss - d->ssets));
- return ss;
- }
-
- /* nobody's old enough?!? -- something's really wrong */
- FDEBUG(("can't find victim to replace!\n"));
- assert(NOTREACHED);
- ERR(REG_ASSERT);
- return d->ssets;
-}
+/*
+ * DFA routines
+ * This file is #included by regexec.c.
+ *
+ * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
+ *
+ * Development of this software was funded, in part, by Cray Research Inc.,
+ * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
+ * Corporation, none of whom are responsible for the results. The author
+ * thanks all of them.
+ *
+ * Redistribution and use in source and binary forms -- with or without
+ * modification -- are permitted for any purpose, provided that
+ * redistributions in source form retain this entire copyright notice and
+ * indicate the origin and nature of any modifications.
+ *
+ * I'd appreciate being given credit for this package in the documentation
+ * of software which uses it, but that is not a requirement.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/*
+ - longest - longest-preferred matching engine
+ ^ static chr *longest(struct vars *, struct dfa *, chr *, chr *, int *);
+ */
+static chr * /* endpoint, or NULL */
+longest(v, d, start, stop, hitstopp)
+struct vars *v; /* used only for debug and exec flags */
+struct dfa *d;
+chr *start; /* where the match should start */
+chr *stop; /* match must end at or before here */
+int *hitstopp; /* record whether hit v->stop, if non-NULL */
+{
+ chr *cp;
+ chr *realstop = (stop == v->stop) ? stop : stop + 1;
+ color co;
+ struct sset *css;
+ struct sset *ss;
+ chr *post;
+ int i;
+ struct colormap *cm = d->cm;
+
+ /* initialize */
+ css = initialize(v, d, start);
+ cp = start;
+ if (hitstopp != NULL)
+ *hitstopp = 0;
+
+ /* startup */
+ FDEBUG(("+++ startup +++\n"));
+ if (cp == v->start) {
+ co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ } else {
+ co = GETCOLOR(cm, *(cp - 1));
+ FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
+ }
+ css = miss(v, d, css, co, cp, start);
+ if (css == NULL)
+ return NULL;
+ css->lastseen = cp;
+
+ /* main loop */
+ if (v->eflags&REG_FTRACE)
+ while (cp < realstop) {
+ FDEBUG(("+++ at c%d +++\n", css - d->ssets));
+ co = GETCOLOR(cm, *cp);
+ FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL)
+ break; /* NOTE BREAK OUT */
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ }
+ else
+ while (cp < realstop) {
+ co = GETCOLOR(cm, *cp);
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL)
+ break; /* NOTE BREAK OUT */
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ }
+
+ /* shutdown */
+ FDEBUG(("+++ shutdown at c%d +++\n", css - d->ssets));
+ if (cp == v->stop && stop == v->stop) {
+ if (hitstopp != NULL)
+ *hitstopp = 1;
+ co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ ss = miss(v, d, css, co, cp, start);
+ /* special case: match ended at eol? */
+ if (ss != NULL && (ss->flags&POSTSTATE))
+ return cp;
+ else if (ss != NULL)
+ ss->lastseen = cp; /* to be tidy */
+ }
+
+ /* find last match, if any */
+ post = d->lastpost;
+ for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
+ if ((ss->flags&POSTSTATE) && post != ss->lastseen &&
+ (post == NULL || post < ss->lastseen))
+ post = ss->lastseen;
+ if (post != NULL) /* found one */
+ return post - 1;
+
+ return NULL;
+}
+
+/*
+ - shortest - shortest-preferred matching engine
+ ^ static chr *shortest(struct vars *, struct dfa *, chr *, chr *, chr *,
+ ^ chr **, int *);
+ */
+static chr * /* endpoint, or NULL */
+shortest(v, d, start, min, max, coldp, hitstopp)
+struct vars *v;
+struct dfa *d;
+chr *start; /* where the match should start */
+chr *min; /* match must end at or after here */
+chr *max; /* match must end at or before here */
+chr **coldp; /* store coldstart pointer here, if nonNULL */
+int *hitstopp; /* record whether hit v->stop, if non-NULL */
+{
+ chr *cp;
+ chr *realmin = (min == v->stop) ? min : min + 1;
+ chr *realmax = (max == v->stop) ? max : max + 1;
+ color co;
+ struct sset *css;
+ struct sset *ss;
+ struct colormap *cm = d->cm;
+
+ /* initialize */
+ css = initialize(v, d, start);
+ cp = start;
+ if (hitstopp != NULL)
+ *hitstopp = 0;
+
+ /* startup */
+ FDEBUG(("--- startup ---\n"));
+ if (cp == v->start) {
+ co = d->cnfa->bos[(v->eflags&REG_NOTBOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ } else {
+ co = GETCOLOR(cm, *(cp - 1));
+ FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
+ }
+ css = miss(v, d, css, co, cp, start);
+ if (css == NULL)
+ return NULL;
+ css->lastseen = cp;
+ ss = css;
+
+ /* main loop */
+ if (v->eflags&REG_FTRACE)
+ while (cp < realmax) {
+ FDEBUG(("--- at c%d ---\n", css - d->ssets));
+ co = GETCOLOR(cm, *cp);
+ FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL)
+ break; /* NOTE BREAK OUT */
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ if ((ss->flags&POSTSTATE) && cp >= realmin)
+ break; /* NOTE BREAK OUT */
+ }
+ else
+ while (cp < realmax) {
+ co = GETCOLOR(cm, *cp);
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL)
+ break; /* NOTE BREAK OUT */
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ if ((ss->flags&POSTSTATE) && cp >= realmin)
+ break; /* NOTE BREAK OUT */
+ }
+
+ if (ss == NULL)
+ return NULL;
+
+ if (coldp != NULL) /* report last no-progress state set, if any */
+ *coldp = lastcold(v, d);
+
+ if ((ss->flags&POSTSTATE) && cp > min) {
+ assert(cp >= realmin);
+ cp--;
+ } else if (cp == v->stop && max == v->stop) {
+ co = d->cnfa->eos[(v->eflags&REG_NOTEOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ ss = miss(v, d, css, co, cp, start);
+ /* match might have ended at eol */
+ if ((ss == NULL || !(ss->flags&POSTSTATE)) && hitstopp != NULL)
+ *hitstopp = 1;
+ }
+
+ if (ss == NULL || !(ss->flags&POSTSTATE))
+ return NULL;
+
+ return cp;
+}
+
+/*
+ - lastcold - determine last point at which no progress had been made
+ ^ static chr *lastcold(struct vars *, struct dfa *);
+ */
+static chr * /* endpoint, or NULL */
+lastcold(v, d)
+struct vars *v;
+struct dfa *d;
+{
+ struct sset *ss;
+ chr *nopr;
+ int i;
+
+ nopr = d->lastnopr;
+ if (nopr == NULL)
+ nopr = v->start;
+ for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--)
+ if ((ss->flags&NOPROGRESS) && nopr < ss->lastseen)
+ nopr = ss->lastseen;
+ return nopr;
+}
+
+/*
+ - newdfa - set up a fresh DFA
+ ^ static struct dfa *newdfa(struct vars *, struct cnfa *,
+ ^ struct colormap *, struct smalldfa *);
+ */
+static struct dfa *
+newdfa(v, cnfa, cm, small)
+struct vars *v;
+struct cnfa *cnfa;
+struct colormap *cm;
+struct smalldfa *small; /* preallocated space, may be NULL */
+{
+ struct dfa *d;
+ size_t nss = cnfa->nstates * 2;
+ int wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
+ struct smalldfa *smallwas = small;
+
+ assert(cnfa != NULL && cnfa->nstates != 0);
+
+ if (nss <= FEWSTATES && cnfa->ncolors <= FEWCOLORS) {
+ assert(wordsper == 1);
+ if (small == NULL) {
+ small = (struct smalldfa *)MALLOC(
+ sizeof(struct smalldfa));
+ if (small == NULL) {
+ ERR(REG_ESPACE);
+ return NULL;
+ }
+ }
+ d = &small->dfa;
+ d->ssets = small->ssets;
+ d->statesarea = small->statesarea;
+ d->work = &d->statesarea[nss];
+ d->outsarea = small->outsarea;
+ d->incarea = small->incarea;
+ d->cptsmalloced = 0;
+ d->mallocarea = (smallwas == NULL) ? (char *)small : NULL;
+ } else {
+ d = (struct dfa *)MALLOC(sizeof(struct dfa));
+ if (d == NULL) {
+ ERR(REG_ESPACE);
+ return NULL;
+ }
+ d->ssets = (struct sset *)MALLOC(nss * sizeof(struct sset));
+ d->statesarea = (unsigned *)MALLOC((nss+WORK) * wordsper *
+ sizeof(unsigned));
+ d->work = &d->statesarea[nss * wordsper];
+ d->outsarea = (struct sset **)MALLOC(nss * cnfa->ncolors *
+ sizeof(struct sset *));
+ d->incarea = (struct arcp *)MALLOC(nss * cnfa->ncolors *
+ sizeof(struct arcp));
+ d->cptsmalloced = 1;
+ d->mallocarea = (char *)d;
+ if (d->ssets == NULL || d->statesarea == NULL ||
+ d->outsarea == NULL || d->incarea == NULL) {
+ freedfa(d);
+ ERR(REG_ESPACE);
+ return NULL;
+ }
+ }
+
+ d->nssets = (v->eflags&REG_SMALL) ? 7 : nss;
+ d->nssused = 0;
+ d->nstates = cnfa->nstates;
+ d->ncolors = cnfa->ncolors;
+ d->wordsper = wordsper;
+ d->cnfa = cnfa;
+ d->cm = cm;
+ d->lastpost = NULL;
+ d->lastnopr = NULL;
+ d->search = d->ssets;
+
+ /* initialization of sset fields is done as needed */
+
+ return d;
+}
+
+/*
+ - freedfa - free a DFA
+ ^ static VOID freedfa(struct dfa *);
+ */
+static VOID
+freedfa(d)
+struct dfa *d;
+{
+ if (d->cptsmalloced) {
+ if (d->ssets != NULL)
+ FREE(d->ssets);
+ if (d->statesarea != NULL)
+ FREE(d->statesarea);
+ if (d->outsarea != NULL)
+ FREE(d->outsarea);
+ if (d->incarea != NULL)
+ FREE(d->incarea);
+ }
+
+ if (d->mallocarea != NULL)
+ FREE(d->mallocarea);
+}
+
+/*
+ - hash - construct a hash code for a bitvector
+ * There are probably better ways, but they're more expensive.
+ ^ static unsigned hash(unsigned *, int);
+ */
+static unsigned
+hash(uv, n)
+unsigned *uv;
+int n;
+{
+ int i;
+ unsigned h;
+
+ h = 0;
+ for (i = 0; i < n; i++)
+ h ^= uv[i];
+ return h;
+}
+
+/*
+ - initialize - hand-craft a cache entry for startup, otherwise get ready
+ ^ static struct sset *initialize(struct vars *, struct dfa *, chr *);
+ */
+static struct sset *
+initialize(v, d, start)
+struct vars *v; /* used only for debug flags */
+struct dfa *d;
+chr *start;
+{
+ struct sset *ss;
+ int i;
+
+ /* is previous one still there? */
+ if (d->nssused > 0 && (d->ssets[0].flags&STARTER))
+ ss = &d->ssets[0];
+ else { /* no, must (re)build it */
+ ss = getvacant(v, d, start, start);
+ for (i = 0; i < d->wordsper; i++)
+ ss->states[i] = 0;
+ BSET(ss->states, d->cnfa->pre);
+ ss->hash = HASH(ss->states, d->wordsper);
+ assert(d->cnfa->pre != d->cnfa->post);
+ ss->flags = STARTER|LOCKED|NOPROGRESS;
+ /* lastseen dealt with below */
+ }
+
+ for (i = 0; i < d->nssused; i++)
+ d->ssets[i].lastseen = NULL;
+ ss->lastseen = start; /* maybe untrue, but harmless */
+ d->lastpost = NULL;
+ d->lastnopr = NULL;
+ return ss;
+}
+
+/*
+ - miss - handle a cache miss
+ ^ static struct sset *miss(struct vars *, struct dfa *, struct sset *,
+ ^ pcolor, chr *, chr *);
+ */
+static struct sset * /* NULL if goes to empty set */
+miss(v, d, css, co, cp, start)
+struct vars *v; /* used only for debug flags */
+struct dfa *d;
+struct sset *css;
+pcolor co;
+chr *cp; /* next chr */
+chr *start; /* where the attempt got started */
+{
+ struct cnfa *cnfa = d->cnfa;
+ int i;
+ unsigned h;
+ struct carc *ca;
+ struct sset *p;
+ int ispost;
+ int noprogress;
+ int gotstate;
+ int dolacons;
+ int sawlacons;
+
+ /* for convenience, we can be called even if it might not be a miss */
+ if (css->outs[co] != NULL) {
+ FDEBUG(("hit\n"));
+ return css->outs[co];
+ }
+ FDEBUG(("miss\n"));
+
+ /* first, what set of states would we end up in? */
+ for (i = 0; i < d->wordsper; i++)
+ d->work[i] = 0;
+ ispost = 0;
+ noprogress = 1;
+ gotstate = 0;
+ for (i = 0; i < d->nstates; i++)
+ if (ISBSET(css->states, i))
+ for (ca = cnfa->states[i]+1; ca->co != COLORLESS; ca++)
+ if (ca->co == co) {
+ BSET(d->work, ca->to);
+ gotstate = 1;
+ if (ca->to == cnfa->post)
+ ispost = 1;
+ if (!cnfa->states[ca->to]->co)
+ noprogress = 0;
+ FDEBUG(("%d -> %d\n", i, ca->to));
+ }
+ dolacons = (gotstate) ? (cnfa->flags&HASLACONS) : 0;
+ sawlacons = 0;
+ while (dolacons) { /* transitive closure */
+ dolacons = 0;
+ for (i = 0; i < d->nstates; i++)
+ if (ISBSET(d->work, i))
+ for (ca = cnfa->states[i]+1; ca->co != COLORLESS;
+ ca++) {
+ if (ca->co <= cnfa->ncolors)
+ continue; /* NOTE CONTINUE */
+ sawlacons = 1;
+ if (ISBSET(d->work, ca->to))
+ continue; /* NOTE CONTINUE */
+ if (!lacon(v, cnfa, cp, ca->co))
+ continue; /* NOTE CONTINUE */
+ BSET(d->work, ca->to);
+ dolacons = 1;
+ if (ca->to == cnfa->post)
+ ispost = 1;
+ if (!cnfa->states[ca->to]->co)
+ noprogress = 0;
+ FDEBUG(("%d :> %d\n", i, ca->to));
+ }
+ }
+ if (!gotstate)
+ return NULL;
+ h = HASH(d->work, d->wordsper);
+
+ /* next, is that in the cache? */
+ for (p = d->ssets, i = d->nssused; i > 0; p++, i--)
+ if (HIT(h, d->work, p, d->wordsper)) {
+ FDEBUG(("cached c%d\n", p - d->ssets));
+ break; /* NOTE BREAK OUT */
+ }
+ if (i == 0) { /* nope, need a new cache entry */
+ p = getvacant(v, d, cp, start);
+ assert(p != css);
+ for (i = 0; i < d->wordsper; i++)
+ p->states[i] = d->work[i];
+ p->hash = h;
+ p->flags = (ispost) ? POSTSTATE : 0;
+ if (noprogress)
+ p->flags |= NOPROGRESS;
+ /* lastseen to be dealt with by caller */
+ }
+
+ if (!sawlacons) { /* lookahead conds. always cache miss */
+ FDEBUG(("c%d[%d]->%d\n", css - d->ssets, co, p - d->ssets));
+ css->outs[co] = p;
+ css->inchain[co] = p->ins;
+ p->ins.ss = css;
+ p->ins.co = (color)co;
+ }
+ return p;
+}
+
+/*
+ - lacon - lookahead-constraint checker for miss()
+ ^ static int lacon(struct vars *, struct cnfa *, chr *, pcolor);
+ */
+static int /* predicate: constraint satisfied? */
+lacon(v, pcnfa, cp, co)
+struct vars *v;
+struct cnfa *pcnfa; /* parent cnfa */
+chr *cp;
+pcolor co; /* "color" of the lookahead constraint */
+{
+ int n;
+ struct subre *sub;
+ struct dfa *d;
+ struct smalldfa sd;
+ chr *end;
+
+ n = co - pcnfa->ncolors;
+ assert(n < v->g->nlacons && v->g->lacons != NULL);
+ FDEBUG(("=== testing lacon %d\n", n));
+ sub = &v->g->lacons[n];
+ d = newdfa(v, &sub->cnfa, &v->g->cmap, &sd);
+ if (d == NULL) {
+ ERR(REG_ESPACE);
+ return 0;
+ }
+ end = longest(v, d, cp, v->stop, (int *)NULL);
+ freedfa(d);
+ FDEBUG(("=== lacon %d match %d\n", n, (end != NULL)));
+ return (sub->subno) ? (end != NULL) : (end == NULL);
+}
+
+/*
+ - getvacant - get a vacant state set
+ * This routine clears out the inarcs and outarcs, but does not otherwise
+ * clear the innards of the state set -- that's up to the caller.
+ ^ static struct sset *getvacant(struct vars *, struct dfa *, chr *, chr *);
+ */
+static struct sset *
+getvacant(v, d, cp, start)
+struct vars *v; /* used only for debug flags */
+struct dfa *d;
+chr *cp;
+chr *start;
+{
+ int i;
+ struct sset *ss;
+ struct sset *p;
+ struct arcp ap;
+ struct arcp lastap;
+ color co;
+
+ ss = pickss(v, d, cp, start);
+ assert(!(ss->flags&LOCKED));
+
+ /* clear out its inarcs, including self-referential ones */
+ ap = ss->ins;
+ while ((p = ap.ss) != NULL) {
+ co = ap.co;
+ FDEBUG(("zapping c%d's %ld outarc\n", p - d->ssets, (long)co));
+ p->outs[co] = NULL;
+ ap = p->inchain[co];
+ p->inchain[co].ss = NULL; /* paranoia */
+ }
+ ss->ins.ss = NULL;
+
+ /* take it off the inarc chains of the ssets reached by its outarcs */
+ for (i = 0; i < d->ncolors; i++) {
+ p = ss->outs[i];
+ assert(p != ss); /* not self-referential */
+ if (p == NULL)
+ continue; /* NOTE CONTINUE */
+ FDEBUG(("del outarc %d from c%d's in chn\n", i, p - d->ssets));
+ if (p->ins.ss == ss && p->ins.co == i)
+ p->ins = ss->inchain[i];
+ else {
+ assert(p->ins.ss != NULL);
+ for (ap = p->ins; ap.ss != NULL &&
+ !(ap.ss == ss && ap.co == i);
+ ap = ap.ss->inchain[ap.co])
+ lastap = ap;
+ assert(ap.ss != NULL);
+ lastap.ss->inchain[lastap.co] = ss->inchain[i];
+ }
+ ss->outs[i] = NULL;
+ ss->inchain[i].ss = NULL;
+ }
+
+ /* if ss was a success state, may need to remember location */
+ if ((ss->flags&POSTSTATE) && ss->lastseen != d->lastpost &&
+ (d->lastpost == NULL || d->lastpost < ss->lastseen))
+ d->lastpost = ss->lastseen;
+
+ /* likewise for a no-progress state */
+ if ((ss->flags&NOPROGRESS) && ss->lastseen != d->lastnopr &&
+ (d->lastnopr == NULL || d->lastnopr < ss->lastseen))
+ d->lastnopr = ss->lastseen;
+
+ return ss;
+}
+
+/*
+ - pickss - pick the next stateset to be used
+ ^ static struct sset *pickss(struct vars *, struct dfa *, chr *, chr *);
+ */
+static struct sset *
+pickss(v, d, cp, start)
+struct vars *v; /* used only for debug flags */
+struct dfa *d;
+chr *cp;
+chr *start;
+{
+ int i;
+ struct sset *ss;
+ struct sset *end;
+ chr *ancient;
+
+ /* shortcut for cases where cache isn't full */
+ if (d->nssused < d->nssets) {
+ i = d->nssused;
+ d->nssused++;
+ ss = &d->ssets[i];
+ FDEBUG(("new c%d\n", i));
+ /* set up innards */
+ ss->states = &d->statesarea[i * d->wordsper];
+ ss->flags = 0;
+ ss->ins.ss = NULL;
+ ss->ins.co = WHITE; /* give it some value */
+ ss->outs = &d->outsarea[i * d->ncolors];
+ ss->inchain = &d->incarea[i * d->ncolors];
+ for (i = 0; i < d->ncolors; i++) {
+ ss->outs[i] = NULL;
+ ss->inchain[i].ss = NULL;
+ }
+ return ss;
+ }
+
+ /* look for oldest, or old enough anyway */
+ if (cp - start > d->nssets*2/3) /* oldest 33% are expendable */
+ ancient = cp - d->nssets*2/3;
+ else
+ ancient = start;
+ for (ss = d->search, end = &d->ssets[d->nssets]; ss < end; ss++)
+ if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
+ !(ss->flags&LOCKED)) {
+ d->search = ss + 1;
+ FDEBUG(("replacing c%d\n", ss - d->ssets));
+ return ss;
+ }
+ for (ss = d->ssets, end = d->search; ss < end; ss++)
+ if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
+ !(ss->flags&LOCKED)) {
+ d->search = ss + 1;
+ FDEBUG(("replacing c%d\n", ss - d->ssets));
+ return ss;
+ }
+
+ /* nobody's old enough?!? -- something's really wrong */
+ FDEBUG(("can't find victim to replace!\n"));
+ assert(NOTREACHED);
+ ERR(REG_ASSERT);
+ return d->ssets;
+}
generated by cgit v0.12 at 2024-11-24 04:07:11 (GMT)