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/* $Header$ */
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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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40 |
longest(v, d, start, stop, hitstopp)
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struct vars *v; /* used only for debug and exec flags */
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42 |
struct dfa *d;
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43 |
chr *start; /* where the match should start */
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44 |
chr *stop; /* match must end at or before here */
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int *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;
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struct sset *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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/* initialize */
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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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/* startup */
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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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72 |
if (css == NULL)
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return NULL;
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css->lastseen = cp;
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75 |
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/* main loop */
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if (v->eflags®_FTRACE)
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while (cp < realstop) {
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FDEBUG(("+++ at c%d +++\n", 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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83 |
if (ss == NULL) {
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84 |
ss = miss(v, d, css, co, cp+1, start);
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85 |
if (ss == NULL)
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break; /* NOTE BREAK OUT */
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87 |
}
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88 |
cp++;
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89 |
ss->lastseen = cp;
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90 |
css = ss;
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91 |
}
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92 |
else
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93 |
while (cp < realstop) {
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94 |
co = GETCOLOR(cm, *cp);
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ss = css->outs[co];
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96 |
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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cp++;
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ss->lastseen = cp;
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css = ss;
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}
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105 |
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/* shutdown */
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FDEBUG(("+++ shutdown at c%d +++\n", 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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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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/* special case: match ended at eol? */
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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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120 |
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/* find last match, if any */
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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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124 |
if ((ss->flags&POSTSTATE) && post != ss->lastseen &&
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125 |
(post == NULL || post < ss->lastseen))
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126 |
post = ss->lastseen;
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127 |
if (post != NULL) /* found one */
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return post - 1;
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129 |
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return NULL;
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131 |
}
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132 |
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133 |
/*
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- shortest - shortest-preferred matching engine
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135 |
^ static chr *shortest(struct vars *, struct dfa *, chr *, chr *, chr *,
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136 |
^ chr **, int *);
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137 |
*/
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138 |
static chr * /* endpoint, or NULL */
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139 |
shortest(v, d, start, min, max, coldp, hitstopp)
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struct vars *v;
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struct dfa *d;
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chr *start; /* where the match should start */
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chr *min; /* match must end at or after here */
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chr *max; /* match must end at or before here */
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chr **coldp; /* store coldstart pointer here, if nonNULL */
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146 |
int *hitstopp; /* record whether hit v->stop, if non-NULL */
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{
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148 |
chr *cp;
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149 |
chr *realmin = (min == v->stop) ? min : min + 1;
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150 |
chr *realmax = (max == v->stop) ? max : max + 1;
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color co;
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152 |
struct sset *css;
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153 |
struct sset *ss;
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struct colormap *cm = d->cm;
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155 |
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/* initialize */
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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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161 |
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/* startup */
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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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174 |
css->lastseen = cp;
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ss = css;
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176 |
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177 |
/* main loop */
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178 |
if (v->eflags®_FTRACE)
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179 |
while (cp < realmax) {
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180 |
FDEBUG(("--- at c%d ---\n", 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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184 |
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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189 |
cp++;
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190 |
ss->lastseen = cp;
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191 |
css = ss;
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192 |
if ((ss->flags&POSTSTATE) && cp >= realmin)
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break; /* NOTE BREAK OUT */
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}
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195 |
else
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196 |
while (cp < realmax) {
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197 |
co = GETCOLOR(cm, *cp);
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ss = css->outs[co];
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199 |
if (ss == NULL) {
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200 |
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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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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209 |
}
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210 |
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211 |
if (ss == NULL)
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return NULL;
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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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217 |
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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/* match might have ended at eol */
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if ((ss == NULL || !(ss->flags&POSTSTATE)) && hitstopp != NULL)
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*hitstopp = 1;
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227 |
}
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229 |
if (ss == NULL || !(ss->flags&POSTSTATE))
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return NULL;
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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(v, d)
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struct vars *v;
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242 |
struct dfa *d;
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243 |
{
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244 |
struct sset *ss;
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chr *nopr;
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int i;
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247 |
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248 |
nopr = d->lastnopr;
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249 |
if (nopr == NULL)
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nopr = v->start;
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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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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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262 |
static struct dfa *
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263 |
newdfa(v, cnfa, cm, small)
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264 |
struct vars *v;
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265 |
struct cnfa *cnfa;
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266 |
struct colormap *cm;
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267 |
struct smalldfa *small; /* preallocated space, may be NULL */
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268 |
{
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269 |
struct dfa *d;
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size_t nss = cnfa->nstates * 2;
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271 |
int wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
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272 |
struct smalldfa *smallwas = small;
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273 |
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274 |
assert(cnfa != NULL && cnfa->nstates != 0);
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275 |
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276 |
if (nss <= FEWSTATES && cnfa->ncolors <= FEWCOLORS) {
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277 |
assert(wordsper == 1);
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278 |
if (small == NULL) {
|
279 |
small = (struct smalldfa *)MALLOC(
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280 |
sizeof(struct smalldfa));
|
281 |
if (small == NULL) {
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282 |
ERR(REG_ESPACE);
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283 |
return NULL;
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284 |
}
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285 |
}
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286 |
d = &small->dfa;
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287 |
d->ssets = small->ssets;
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288 |
d->statesarea = small->statesarea;
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289 |
d->work = &d->statesarea[nss];
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290 |
d->outsarea = small->outsarea;
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291 |
d->incarea = small->incarea;
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292 |
d->cptsmalloced = 0;
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293 |
d->mallocarea = (smallwas == NULL) ? (char *)small : NULL;
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294 |
} else {
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295 |
d = (struct dfa *)MALLOC(sizeof(struct dfa));
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296 |
if (d == NULL) {
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297 |
ERR(REG_ESPACE);
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298 |
return NULL;
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299 |
}
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300 |
d->ssets = (struct sset *)MALLOC(nss * sizeof(struct sset));
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301 |
d->statesarea = (unsigned *)MALLOC((nss+WORK) * wordsper *
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302 |
sizeof(unsigned));
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d->work = &d->statesarea[nss * wordsper];
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304 |
d->outsarea = (struct sset **)MALLOC(nss * cnfa->ncolors *
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305 |
sizeof(struct sset *));
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306 |
d->incarea = (struct arcp *)MALLOC(nss * cnfa->ncolors *
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307 |
sizeof(struct arcp));
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308 |
d->cptsmalloced = 1;
|
309 |
d->mallocarea = (char *)d;
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310 |
if (d->ssets == NULL || d->statesarea == NULL ||
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311 |
d->outsarea == NULL || d->incarea == NULL) {
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312 |
freedfa(d);
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313 |
ERR(REG_ESPACE);
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314 |
return NULL;
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315 |
}
|
316 |
}
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317 |
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318 |
d->nssets = (v->eflags®_SMALL) ? 7 : nss;
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319 |
d->nssused = 0;
|
320 |
d->nstates = cnfa->nstates;
|
321 |
d->ncolors = cnfa->ncolors;
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322 |
d->wordsper = wordsper;
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323 |
d->cnfa = cnfa;
|
324 |
d->cm = cm;
|
325 |
d->lastpost = NULL;
|
326 |
d->lastnopr = NULL;
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327 |
d->search = d->ssets;
|
328 |
|
329 |
/* initialization of sset fields is done as needed */
|
330 |
|
331 |
return d;
|
332 |
}
|
333 |
|
334 |
/*
|
335 |
- freedfa - free a DFA
|
336 |
^ static VOID freedfa(struct dfa *);
|
337 |
*/
|
338 |
static VOID
|
339 |
freedfa(d)
|
340 |
struct dfa *d;
|
341 |
{
|
342 |
if (d->cptsmalloced) {
|
343 |
if (d->ssets != NULL)
|
344 |
FREE(d->ssets);
|
345 |
if (d->statesarea != NULL)
|
346 |
FREE(d->statesarea);
|
347 |
if (d->outsarea != NULL)
|
348 |
FREE(d->outsarea);
|
349 |
if (d->incarea != NULL)
|
350 |
FREE(d->incarea);
|
351 |
}
|
352 |
|
353 |
if (d->mallocarea != NULL)
|
354 |
FREE(d->mallocarea);
|
355 |
}
|
356 |
|
357 |
/*
|
358 |
- hash - construct a hash code for a bitvector
|
359 |
* There are probably better ways, but they're more expensive.
|
360 |
^ static unsigned hash(unsigned *, int);
|
361 |
*/
|
362 |
static unsigned
|
363 |
hash(uv, n)
|
364 |
unsigned *uv;
|
365 |
int n;
|
366 |
{
|
367 |
int i;
|
368 |
unsigned h;
|
369 |
|
370 |
h = 0;
|
371 |
for (i = 0; i < n; i++)
|
372 |
h ^= uv[i];
|
373 |
return h;
|
374 |
}
|
375 |
|
376 |
/*
|
377 |
- initialize - hand-craft a cache entry for startup, otherwise get ready
|
378 |
^ static struct sset *initialize(struct vars *, struct dfa *, chr *);
|
379 |
*/
|
380 |
static struct sset *
|
381 |
initialize(v, d, start)
|
382 |
struct vars *v; /* used only for debug flags */
|
383 |
struct dfa *d;
|
384 |
chr *start;
|
385 |
{
|
386 |
struct sset *ss;
|
387 |
int i;
|
388 |
|
389 |
/* is previous one still there? */
|
390 |
if (d->nssused > 0 && (d->ssets[0].flags&STARTER))
|
391 |
ss = &d->ssets[0];
|
392 |
else { /* no, must (re)build it */
|
393 |
ss = getvacant(v, d, start, start);
|
394 |
for (i = 0; i < d->wordsper; i++)
|
395 |
ss->states[i] = 0;
|
396 |
BSET(ss->states, d->cnfa->pre);
|
397 |
ss->hash = HASH(ss->states, d->wordsper);
|
398 |
assert(d->cnfa->pre != d->cnfa->post);
|
399 |
ss->flags = STARTER|LOCKED|NOPROGRESS;
|
400 |
/* lastseen dealt with below */
|
401 |
}
|
402 |
|
403 |
for (i = 0; i < d->nssused; i++)
|
404 |
d->ssets[i].lastseen = NULL;
|
405 |
ss->lastseen = start; /* maybe untrue, but harmless */
|
406 |
d->lastpost = NULL;
|
407 |
d->lastnopr = NULL;
|
408 |
return ss;
|
409 |
}
|
410 |
|
411 |
/*
|
412 |
- miss - handle a cache miss
|
413 |
^ static struct sset *miss(struct vars *, struct dfa *, struct sset *,
|
414 |
^ pcolor, chr *, chr *);
|
415 |
*/
|
416 |
static struct sset * /* NULL if goes to empty set */
|
417 |
miss(v, d, css, co, cp, start)
|
418 |
struct vars *v; /* used only for debug flags */
|
419 |
struct dfa *d;
|
420 |
struct sset *css;
|
421 |
pcolor co;
|
422 |
chr *cp; /* next chr */
|
423 |
chr *start; /* where the attempt got started */
|
424 |
{
|
425 |
struct cnfa *cnfa = d->cnfa;
|
426 |
int i;
|
427 |
unsigned h;
|
428 |
struct carc *ca;
|
429 |
struct sset *p;
|
430 |
int ispost;
|
431 |
int noprogress;
|
432 |
int gotstate;
|
433 |
int dolacons;
|
434 |
int sawlacons;
|
435 |
|
436 |
/* for convenience, we can be called even if it might not be a miss */
|
437 |
if (css->outs[co] != NULL) {
|
438 |
FDEBUG(("hit\n"));
|
439 |
return css->outs[co];
|
440 |
}
|
441 |
FDEBUG(("miss\n"));
|
442 |
|
443 |
/* first, what set of states would we end up in? */
|
444 |
for (i = 0; i < d->wordsper; i++)
|
445 |
d->work[i] = 0;
|
446 |
ispost = 0;
|
447 |
noprogress = 1;
|
448 |
gotstate = 0;
|
449 |
for (i = 0; i < d->nstates; i++)
|
450 |
if (ISBSET(css->states, i))
|
451 |
for (ca = cnfa->states[i]+1; ca->co != COLORLESS; ca++)
|
452 |
if (ca->co == co) {
|
453 |
BSET(d->work, ca->to);
|
454 |
gotstate = 1;
|
455 |
if (ca->to == cnfa->post)
|
456 |
ispost = 1;
|
457 |
if (!cnfa->states[ca->to]->co)
|
458 |
noprogress = 0;
|
459 |
FDEBUG(("%d -> %d\n", i, ca->to));
|
460 |
}
|
461 |
dolacons = (gotstate) ? (cnfa->flags&HASLACONS) : 0;
|
462 |
sawlacons = 0;
|
463 |
while (dolacons) { /* transitive closure */
|
464 |
dolacons = 0;
|
465 |
for (i = 0; i < d->nstates; i++)
|
466 |
if (ISBSET(d->work, i))
|
467 |
for (ca = cnfa->states[i]+1; ca->co != COLORLESS;
|
468 |
ca++) {
|
469 |
if (ca->co <= cnfa->ncolors)
|
470 |
continue; /* NOTE CONTINUE */
|
471 |
sawlacons = 1;
|
472 |
if (ISBSET(d->work, ca->to))
|
473 |
continue; /* NOTE CONTINUE */
|
474 |
if (!lacon(v, cnfa, cp, ca->co))
|
475 |
continue; /* NOTE CONTINUE */
|
476 |
BSET(d->work, ca->to);
|
477 |
dolacons = 1;
|
478 |
if (ca->to == cnfa->post)
|
479 |
ispost = 1;
|
480 |
if (!cnfa->states[ca->to]->co)
|
481 |
noprogress = 0;
|
482 |
FDEBUG(("%d :> %d\n", i, ca->to));
|
483 |
}
|
484 |
}
|
485 |
if (!gotstate)
|
486 |
return NULL;
|
487 |
h = HASH(d->work, d->wordsper);
|
488 |
|
489 |
/* next, is that in the cache? */
|
490 |
for (p = d->ssets, i = d->nssused; i > 0; p++, i--)
|
491 |
if (HIT(h, d->work, p, d->wordsper)) {
|
492 |
FDEBUG(("cached c%d\n", p - d->ssets));
|
493 |
break; /* NOTE BREAK OUT */
|
494 |
}
|
495 |
if (i == 0) { /* nope, need a new cache entry */
|
496 |
p = getvacant(v, d, cp, start);
|
497 |
assert(p != css);
|
498 |
for (i = 0; i < d->wordsper; i++)
|
499 |
p->states[i] = d->work[i];
|
500 |
p->hash = h;
|
501 |
p->flags = (ispost) ? POSTSTATE : 0;
|
502 |
if (noprogress)
|
503 |
p->flags |= NOPROGRESS;
|
504 |
/* lastseen to be dealt with by caller */
|
505 |
}
|
506 |
|
507 |
if (!sawlacons) { /* lookahead conds. always cache miss */
|
508 |
FDEBUG(("c%d[%d]->c%d\n", css - d->ssets, co, p - d->ssets));
|
509 |
css->outs[co] = p;
|
510 |
css->inchain[co] = p->ins;
|
511 |
p->ins.ss = css;
|
512 |
p->ins.co = (color)co;
|
513 |
}
|
514 |
return p;
|
515 |
}
|
516 |
|
517 |
/*
|
518 |
- lacon - lookahead-constraint checker for miss()
|
519 |
^ static int lacon(struct vars *, struct cnfa *, chr *, pcolor);
|
520 |
*/
|
521 |
static int /* predicate: constraint satisfied? */
|
522 |
lacon(v, pcnfa, cp, co)
|
523 |
struct vars *v;
|
524 |
struct cnfa *pcnfa; /* parent cnfa */
|
525 |
chr *cp;
|
526 |
pcolor co; /* "color" of the lookahead constraint */
|
527 |
{
|
528 |
int n;
|
529 |
struct subre *sub;
|
530 |
struct dfa *d;
|
531 |
struct smalldfa sd;
|
532 |
chr *end;
|
533 |
|
534 |
n = co - pcnfa->ncolors;
|
535 |
assert(n < v->g->nlacons && v->g->lacons != NULL);
|
536 |
FDEBUG(("=== testing lacon %d\n", n));
|
537 |
sub = &v->g->lacons[n];
|
538 |
d = newdfa(v, &sub->cnfa, &v->g->cmap, &sd);
|
539 |
if (d == NULL) {
|
540 |
ERR(REG_ESPACE);
|
541 |
return 0;
|
542 |
}
|
543 |
end = longest(v, d, cp, v->stop, (int *)NULL);
|
544 |
freedfa(d);
|
545 |
FDEBUG(("=== lacon %d match %d\n", n, (end != NULL)));
|
546 |
return (sub->subno) ? (end != NULL) : (end == NULL);
|
547 |
}
|
548 |
|
549 |
/*
|
550 |
- getvacant - get a vacant state set
|
551 |
* This routine clears out the inarcs and outarcs, but does not otherwise
|
552 |
* clear the innards of the state set -- that's up to the caller.
|
553 |
^ static struct sset *getvacant(struct vars *, struct dfa *, chr *, chr *);
|
554 |
*/
|
555 |
static struct sset *
|
556 |
getvacant(v, d, cp, start)
|
557 |
struct vars *v; /* used only for debug flags */
|
558 |
struct dfa *d;
|
559 |
chr *cp;
|
560 |
chr *start;
|
561 |
{
|
562 |
int i;
|
563 |
struct sset *ss;
|
564 |
struct sset *p;
|
565 |
struct arcp ap;
|
566 |
struct arcp lastap;
|
567 |
color co;
|
568 |
|
569 |
ss = pickss(v, d, cp, start);
|
570 |
assert(!(ss->flags&LOCKED));
|
571 |
|
572 |
/* clear out its inarcs, including self-referential ones */
|
573 |
ap = ss->ins;
|
574 |
while ((p = ap.ss) != NULL) {
|
575 |
co = ap.co;
|
576 |
FDEBUG(("zapping c%d's %ld outarc\n", p - d->ssets, (long)co));
|
577 |
p->outs[co] = NULL;
|
578 |
ap = p->inchain[co];
|
579 |
p->inchain[co].ss = NULL; /* paranoia */
|
580 |
}
|
581 |
ss->ins.ss = NULL;
|
582 |
|
583 |
/* take it off the inarc chains of the ssets reached by its outarcs */
|
584 |
for (i = 0; i < d->ncolors; i++) {
|
585 |
p = ss->outs[i];
|
586 |
assert(p != ss); /* not self-referential */
|
587 |
if (p == NULL)
|
588 |
continue; /* NOTE CONTINUE */
|
589 |
FDEBUG(("del outarc %d from c%d's in chn\n", i, p - d->ssets));
|
590 |
if (p->ins.ss == ss && p->ins.co == i)
|
591 |
p->ins = ss->inchain[i];
|
592 |
else {
|
593 |
assert(p->ins.ss != NULL);
|
594 |
for (ap = p->ins; ap.ss != NULL &&
|
595 |
!(ap.ss == ss && ap.co == i);
|
596 |
ap = ap.ss->inchain[ap.co])
|
597 |
lastap = ap;
|
598 |
assert(ap.ss != NULL);
|
599 |
lastap.ss->inchain[lastap.co] = ss->inchain[i];
|
600 |
}
|
601 |
ss->outs[i] = NULL;
|
602 |
ss->inchain[i].ss = NULL;
|
603 |
}
|
604 |
|
605 |
/* if ss was a success state, may need to remember location */
|
606 |
if ((ss->flags&POSTSTATE) && ss->lastseen != d->lastpost &&
|
607 |
(d->lastpost == NULL || d->lastpost < ss->lastseen))
|
608 |
d->lastpost = ss->lastseen;
|
609 |
|
610 |
/* likewise for a no-progress state */
|
611 |
if ((ss->flags&NOPROGRESS) && ss->lastseen != d->lastnopr &&
|
612 |
(d->lastnopr == NULL || d->lastnopr < ss->lastseen))
|
613 |
d->lastnopr = ss->lastseen;
|
614 |
|
615 |
return ss;
|
616 |
}
|
617 |
|
618 |
/*
|
619 |
- pickss - pick the next stateset to be used
|
620 |
^ static struct sset *pickss(struct vars *, struct dfa *, chr *, chr *);
|
621 |
*/
|
622 |
static struct sset *
|
623 |
pickss(v, d, cp, start)
|
624 |
struct vars *v; /* used only for debug flags */
|
625 |
struct dfa *d;
|
626 |
chr *cp;
|
627 |
chr *start;
|
628 |
{
|
629 |
int i;
|
630 |
struct sset *ss;
|
631 |
struct sset *end;
|
632 |
chr *ancient;
|
633 |
|
634 |
/* shortcut for cases where cache isn't full */
|
635 |
if (d->nssused < d->nssets) {
|
636 |
i = d->nssused;
|
637 |
d->nssused++;
|
638 |
ss = &d->ssets[i];
|
639 |
FDEBUG(("new c%d\n", i));
|
640 |
/* set up innards */
|
641 |
ss->states = &d->statesarea[i * d->wordsper];
|
642 |
ss->flags = 0;
|
643 |
ss->ins.ss = NULL;
|
644 |
ss->ins.co = WHITE; /* give it some value */
|
645 |
ss->outs = &d->outsarea[i * d->ncolors];
|
646 |
ss->inchain = &d->incarea[i * d->ncolors];
|
647 |
for (i = 0; i < d->ncolors; i++) {
|
648 |
ss->outs[i] = NULL;
|
649 |
ss->inchain[i].ss = NULL;
|
650 |
}
|
651 |
return ss;
|
652 |
}
|
653 |
|
654 |
/* look for oldest, or old enough anyway */
|
655 |
if (cp - start > d->nssets*2/3) /* oldest 33% are expendable */
|
656 |
ancient = cp - d->nssets*2/3;
|
657 |
else
|
658 |
ancient = start;
|
659 |
for (ss = d->search, end = &d->ssets[d->nssets]; ss < end; ss++)
|
660 |
if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
|
661 |
!(ss->flags&LOCKED)) {
|
662 |
d->search = ss + 1;
|
663 |
FDEBUG(("replacing c%d\n", ss - d->ssets));
|
664 |
return ss;
|
665 |
}
|
666 |
for (ss = d->ssets, end = d->search; ss < end; ss++)
|
667 |
if ((ss->lastseen == NULL || ss->lastseen < ancient) &&
|
668 |
!(ss->flags&LOCKED)) {
|
669 |
d->search = ss + 1;
|
670 |
FDEBUG(("replacing c%d\n", ss - d->ssets));
|
671 |
return ss;
|
672 |
}
|
673 |
|
674 |
/* nobody's old enough?!? -- something's really wrong */
|
675 |
FDEBUG(("can't find victim to replace!\n"));
|
676 |
assert(NOTREACHED);
|
677 |
ERR(REG_ASSERT);
|
678 |
return d->ssets;
|
679 |
}
|
680 |
|
681 |
/* $History: rege_dfa.c $
|
682 |
*
|
683 |
* ***************** Version 1 *****************
|
684 |
* User: Dtashley Date: 1/02/01 Time: 12:10a
|
685 |
* Created in $/IjuScripter, IjuConsole/Source/Tcl Base
|
686 |
* Initial check-in.
|
687 |
*/
|
688 |
|
689 |
/* End of REGE_DFA.C */ |