806 lines
19 KiB
C
806 lines
19 KiB
C
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/*
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* DFA routines
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* This file is #included by regexec.c.
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*
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* Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
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*
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* Development of this software was funded, in part, by Cray Research Inc.,
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* UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
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* Corporation, none of whom are responsible for the results. The author
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* thanks all of them.
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*
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* Redistribution and use in source and binary forms -- with or without
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* modification -- are permitted for any purpose, provided that
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* redistributions in source form retain this entire copyright notice and
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* indicate the origin and nature of any modifications.
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*
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* I'd appreciate being given credit for this package in the documentation
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* of software which uses it, but that is not a requirement.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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/*
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- longest - longest-preferred matching engine
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^ static chr *longest(struct vars *, struct dfa *, chr *, chr *, int *);
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*/
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static chr * /* endpoint, or NULL */
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longest(
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struct vars *const v, /* used only for debug and exec flags */
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struct dfa *const d,
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chr *const start, /* where the match should start */
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chr *const stop, /* match must end at or before here */
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int *const hitstopp) /* record whether hit v->stop, if non-NULL */
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{
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chr *cp;
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chr *realstop = (stop == v->stop) ? stop : stop + 1;
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color co;
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struct sset *css, *ss;
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chr *post;
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int i;
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struct colormap *cm = d->cm;
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/*
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* Initialize.
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*/
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css = initialize(v, d, start);
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cp = start;
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if (hitstopp != NULL) {
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*hitstopp = 0;
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}
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/*
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* Startup.
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*/
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FDEBUG(("+++ startup +++\n"));
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if (cp == v->start) {
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co = d->cnfa->bos[(v->eflags®_NOTBOL) ? 0 : 1];
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FDEBUG(("color %ld\n", (long)co));
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} else {
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co = GETCOLOR(cm, *(cp - 1));
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FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
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}
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css = miss(v, d, css, co, cp, start);
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if (css == NULL) {
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return NULL;
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}
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css->lastseen = cp;
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/*
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* Main loop.
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*/
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if (v->eflags®_FTRACE) {
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while (cp < realstop) {
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FDEBUG(("+++ at c%d +++\n", (int) (css - d->ssets)));
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co = GETCOLOR(cm, *cp);
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FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
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ss = css->outs[co];
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if (ss == NULL) {
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ss = miss(v, d, css, co, cp+1, start);
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if (ss == NULL) {
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break; /* NOTE BREAK OUT */
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}
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}
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cp++;
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ss->lastseen = cp;
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css = ss;
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}
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} else {
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while (cp < realstop) {
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co = GETCOLOR(cm, *cp);
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ss = css->outs[co];
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if (ss == NULL) {
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ss = miss(v, d, css, co, cp+1, start);
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if (ss == NULL) {
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break; /* NOTE BREAK OUT */
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}
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}
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cp++;
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ss->lastseen = cp;
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css = ss;
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}
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}
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/*
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* Shutdown.
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*/
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FDEBUG(("+++ shutdown at c%d +++\n", (int) (css - d->ssets)));
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if (cp == v->stop && stop == v->stop) {
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if (hitstopp != NULL) {
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*hitstopp = 1;
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}
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co = d->cnfa->eos[(v->eflags®_NOTEOL) ? 0 : 1];
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FDEBUG(("color %ld\n", (long)co));
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ss = miss(v, d, css, co, cp, start);
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/*
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* Special case: match ended at eol?
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*/
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if (ss != NULL && (ss->flags&POSTSTATE)) {
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return cp;
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} else if (ss != NULL) {
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ss->lastseen = cp; /* to be tidy */
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}
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}
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/*
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* Find last match, if any.
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*/
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post = d->lastpost;
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for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--) {
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if ((ss->flags&POSTSTATE) && (post != ss->lastseen) &&
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(post == NULL || post < ss->lastseen)) {
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post = ss->lastseen;
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}
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}
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if (post != NULL) { /* found one */
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return post - 1;
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}
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return NULL;
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}
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/*
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- shortest - shortest-preferred matching engine
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^ static chr *shortest(struct vars *, struct dfa *, chr *, chr *, chr *,
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^ chr **, int *);
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*/
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static chr * /* endpoint, or NULL */
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shortest(
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struct vars *const v,
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struct dfa *const d,
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chr *const start, /* where the match should start */
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chr *const min, /* match must end at or after here */
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chr *const max, /* match must end at or before here */
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chr **const coldp, /* store coldstart pointer here, if nonNULL */
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int *const hitstopp) /* record whether hit v->stop, if non-NULL */
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{
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chr *cp;
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chr *realmin = (min == v->stop) ? min : min + 1;
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chr *realmax = (max == v->stop) ? max : max + 1;
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color co;
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struct sset *css, *ss;
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struct colormap *cm = d->cm;
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/*
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* Initialize.
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*/
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css = initialize(v, d, start);
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cp = start;
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if (hitstopp != NULL) {
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*hitstopp = 0;
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}
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/*
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* Startup.
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*/
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FDEBUG(("--- startup ---\n"));
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if (cp == v->start) {
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co = d->cnfa->bos[(v->eflags®_NOTBOL) ? 0 : 1];
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FDEBUG(("color %ld\n", (long)co));
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} else {
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co = GETCOLOR(cm, *(cp - 1));
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FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
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}
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css = miss(v, d, css, co, cp, start);
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if (css == NULL) {
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return NULL;
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}
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css->lastseen = cp;
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ss = css;
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/*
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* Main loop.
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*/
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if (v->eflags®_FTRACE) {
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while (cp < realmax) {
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FDEBUG(("--- at c%d ---\n", (int) (css - d->ssets)));
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co = GETCOLOR(cm, *cp);
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FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
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ss = css->outs[co];
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if (ss == NULL) {
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ss = miss(v, d, css, co, cp+1, start);
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if (ss == NULL) {
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break; /* NOTE BREAK OUT */
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}
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}
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cp++;
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ss->lastseen = cp;
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css = ss;
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if ((ss->flags&POSTSTATE) && cp >= realmin) {
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break; /* NOTE BREAK OUT */
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}
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}
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} else {
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while (cp < realmax) {
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co = GETCOLOR(cm, *cp);
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ss = css->outs[co];
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if (ss == NULL) {
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ss = miss(v, d, css, co, cp+1, start);
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if (ss == NULL) {
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break; /* NOTE BREAK OUT */
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}
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}
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cp++;
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ss->lastseen = cp;
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css = ss;
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if ((ss->flags&POSTSTATE) && cp >= realmin) {
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break; /* NOTE BREAK OUT */
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}
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}
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}
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if (ss == NULL) {
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return NULL;
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}
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if (coldp != NULL) { /* report last no-progress state set, if any */
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*coldp = lastCold(v, d);
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}
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if ((ss->flags&POSTSTATE) && cp > min) {
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assert(cp >= realmin);
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cp--;
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} else if (cp == v->stop && max == v->stop) {
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co = d->cnfa->eos[(v->eflags®_NOTEOL) ? 0 : 1];
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FDEBUG(("color %ld\n", (long)co));
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ss = miss(v, d, css, co, cp, start);
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/*
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* Match might have ended at eol.
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*/
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if ((ss == NULL || !(ss->flags&POSTSTATE)) && hitstopp != NULL) {
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*hitstopp = 1;
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}
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}
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if (ss == NULL || !(ss->flags&POSTSTATE)) {
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return NULL;
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}
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return cp;
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}
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/*
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- lastCold - determine last point at which no progress had been made
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^ static chr *lastCold(struct vars *, struct dfa *);
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*/
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static chr * /* endpoint, or NULL */
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lastCold(
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struct vars *const v,
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struct dfa *const d)
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{
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struct sset *ss;
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chr *nopr = d->lastnopr;
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int i;
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if (nopr == NULL) {
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nopr = v->start;
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}
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for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--) {
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if ((ss->flags&NOPROGRESS) && nopr < ss->lastseen) {
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nopr = ss->lastseen;
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}
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}
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return nopr;
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}
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/*
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- newDFA - set up a fresh DFA
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^ static struct dfa *newDFA(struct vars *, struct cnfa *,
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^ struct colormap *, struct smalldfa *);
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*/
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static struct dfa *
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newDFA(
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struct vars *const v,
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struct cnfa *const cnfa,
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struct colormap *const cm,
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struct smalldfa *sml) /* preallocated space, may be NULL */
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{
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struct dfa *d;
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size_t nss = cnfa->nstates * 2;
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int wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
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struct smalldfa *smallwas = sml;
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assert(cnfa != NULL && cnfa->nstates != 0);
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if (nss <= FEWSTATES && cnfa->ncolors <= FEWCOLORS) {
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assert(wordsper == 1);
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if (sml == NULL) {
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sml = (struct smalldfa *) MALLOC(sizeof(struct smalldfa));
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if (sml == NULL) {
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ERR(REG_ESPACE);
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return NULL;
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}
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}
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d = &sml->dfa;
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d->ssets = sml->ssets;
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d->statesarea = sml->statesarea;
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d->work = &d->statesarea[nss];
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d->outsarea = sml->outsarea;
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d->incarea = sml->incarea;
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d->cptsmalloced = 0;
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d->mallocarea = (smallwas == NULL) ? (char *)sml : NULL;
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} else {
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d = (struct dfa *) MALLOC(sizeof(struct dfa));
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if (d == NULL) {
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ERR(REG_ESPACE);
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return NULL;
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}
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d->ssets = (struct sset *) MALLOC(nss * sizeof(struct sset));
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d->statesarea = (unsigned *)
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MALLOC((nss+WORK) * wordsper * sizeof(unsigned));
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d->work = &d->statesarea[nss * wordsper];
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d->outsarea = (struct sset **)
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MALLOC(nss * cnfa->ncolors * sizeof(struct sset *));
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d->incarea = (struct arcp *)
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MALLOC(nss * cnfa->ncolors * sizeof(struct arcp));
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d->cptsmalloced = 1;
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d->mallocarea = (char *)d;
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if (d->ssets == NULL || d->statesarea == NULL ||
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d->outsarea == NULL || d->incarea == NULL) {
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freeDFA(d);
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ERR(REG_ESPACE);
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|
|
return NULL;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
d->nssets = (v->eflags®_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(
|
|||
|
|
struct dfa *const 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(
|
|||
|
|
unsigned *const uv,
|
|||
|
|
const 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(
|
|||
|
|
struct vars *const v, /* used only for debug flags */
|
|||
|
|
struct dfa *const d,
|
|||
|
|
chr *const 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 = getVacantSS(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(
|
|||
|
|
struct vars *const v, /* used only for debug flags */
|
|||
|
|
struct dfa *const d,
|
|||
|
|
struct sset *const css,
|
|||
|
|
const pcolor co,
|
|||
|
|
chr *const cp, /* next chr */
|
|||
|
|
chr *const start) /* where the attempt got started */
|
|||
|
|
{
|
|||
|
|
struct cnfa *cnfa = d->cnfa;
|
|||
|
|
unsigned h;
|
|||
|
|
struct carc *ca;
|
|||
|
|
struct sset *p;
|
|||
|
|
int i, isPost, noProgress, gotState, doLAConstraints, sawLAConstraints;
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* 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]; ca->co != COLORLESS; ca++) {
|
|||
|
|
if (ca->co == co) {
|
|||
|
|
BSET(d->work, ca->to);
|
|||
|
|
gotState = 1;
|
|||
|
|
if (ca->to == cnfa->post) {
|
|||
|
|
isPost = 1;
|
|||
|
|
}
|
|||
|
|
if (!(cnfa->stflags[ca->to] & CNFA_NOPROGRESS)) {
|
|||
|
|
noProgress = 0;
|
|||
|
|
}
|
|||
|
|
FDEBUG(("%d -> %d\n", i, ca->to));
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
doLAConstraints = (gotState ? (cnfa->flags&HASLACONS) : 0);
|
|||
|
|
sawLAConstraints = 0;
|
|||
|
|
while (doLAConstraints) { /* transitive closure */
|
|||
|
|
doLAConstraints = 0;
|
|||
|
|
for (i = 0; i < d->nstates; i++) {
|
|||
|
|
if (ISBSET(d->work, i)) {
|
|||
|
|
for (ca = cnfa->states[i]; ca->co != COLORLESS; ca++) {
|
|||
|
|
if (ca->co < cnfa->ncolors) {
|
|||
|
|
continue; /* NOTE CONTINUE */
|
|||
|
|
}
|
|||
|
|
sawLAConstraints = 1;
|
|||
|
|
if (ISBSET(d->work, ca->to)) {
|
|||
|
|
continue; /* NOTE CONTINUE */
|
|||
|
|
}
|
|||
|
|
if (!checkLAConstraint(v, cnfa, cp, ca->co)) {
|
|||
|
|
continue; /* NOTE CONTINUE */
|
|||
|
|
}
|
|||
|
|
BSET(d->work, ca->to);
|
|||
|
|
doLAConstraints = 1;
|
|||
|
|
if (ca->to == cnfa->post) {
|
|||
|
|
isPost = 1;
|
|||
|
|
}
|
|||
|
|
if (!(cnfa->stflags[ca->to] & CNFA_NOPROGRESS)) {
|
|||
|
|
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", (int) (p - d->ssets)));
|
|||
|
|
break; /* NOTE BREAK OUT */
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
if (i == 0) { /* nope, need a new cache entry */
|
|||
|
|
p = getVacantSS(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 (!sawLAConstraints) { /* lookahead conds. always cache miss */
|
|||
|
|
FDEBUG(("c%d[%d]->c%d\n",
|
|||
|
|
(int) (css - d->ssets), co, (int) (p - d->ssets)));
|
|||
|
|
css->outs[co] = p;
|
|||
|
|
css->inchain[co] = p->ins;
|
|||
|
|
p->ins.ss = css;
|
|||
|
|
p->ins.co = (color) co;
|
|||
|
|
}
|
|||
|
|
return p;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
- checkLAConstraint - lookahead-constraint checker for miss()
|
|||
|
|
^ static int checkLAConstraint(struct vars *, struct cnfa *, chr *, pcolor);
|
|||
|
|
*/
|
|||
|
|
static int /* predicate: constraint satisfied? */
|
|||
|
|
checkLAConstraint(
|
|||
|
|
struct vars *const v,
|
|||
|
|
struct cnfa *const pcnfa, /* parent cnfa */
|
|||
|
|
chr *const cp,
|
|||
|
|
const 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, NULL);
|
|||
|
|
freeDFA(d);
|
|||
|
|
FDEBUG(("=== lacon %d match %d\n", n, (end != NULL)));
|
|||
|
|
return (sub->subno) ? (end != NULL) : (end == NULL);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
- getVacantSS - 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 *getVacantSS(struct vars *, struct dfa *, chr *, chr *);
|
|||
|
|
*/
|
|||
|
|
static struct sset *
|
|||
|
|
getVacantSS(
|
|||
|
|
struct vars *const v, /* used only for debug flags */
|
|||
|
|
struct dfa *const d,
|
|||
|
|
chr *const cp,
|
|||
|
|
chr *const start)
|
|||
|
|
{
|
|||
|
|
int i;
|
|||
|
|
struct sset *ss, *p;
|
|||
|
|
struct arcp ap, lastap = {NULL, 0}; /* silence gcc 4 warning */
|
|||
|
|
color co;
|
|||
|
|
|
|||
|
|
ss = pickNextSS(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", (int) (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, (int) (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;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
- pickNextSS - pick the next stateset to be used
|
|||
|
|
^ static struct sset *pickNextSS(struct vars *, struct dfa *, chr *, chr *);
|
|||
|
|
*/
|
|||
|
|
static struct sset *
|
|||
|
|
pickNextSS(
|
|||
|
|
struct vars *const v, /* used only for debug flags */
|
|||
|
|
struct dfa *const d,
|
|||
|
|
chr *const cp,
|
|||
|
|
chr *const start)
|
|||
|
|
{
|
|||
|
|
int i;
|
|||
|
|
struct sset *ss, *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", (int) (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", (int) (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;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Local Variables:
|
|||
|
|
* mode: c
|
|||
|
|
* c-basic-offset: 4
|
|||
|
|
* fill-column: 78
|
|||
|
|
* End:
|
|||
|
|
*/
|