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+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
+ *
+ * @(#)engine.c 8.5 (Berkeley) 3/20/94
+ */
+
+/*
+ * The matching engine and friends. This file is #included by regexec.c
+ * after suitable #defines of a variety of macros used herein, so that
+ * different state representations can be used without duplicating masses
+ * of code.
+ */
+
+#ifdef SNAMES
+#define matcher smatcher
+#define fast sfast
+#define slow sslow
+#define dissect sdissect
+#define backref sbackref
+#define step sstep
+#define print sprint
+#define at sat
+#define match smat
+#endif
+#ifdef LNAMES
+#define matcher lmatcher
+#define fast lfast
+#define slow lslow
+#define dissect ldissect
+#define backref lbackref
+#define step lstep
+#define print lprint
+#define at lat
+#define match lmat
+#endif
+
+/* another structure passed up and down to avoid zillions of parameters */
+struct match {
+ struct re_guts *g;
+ int eflags;
+ regmatch_t *pmatch; /* [nsub+1] (0 element unused) */
+ char *offp; /* offsets work from here */
+ char *beginp; /* start of string -- virtual NUL precedes */
+ char *endp; /* end of string -- virtual NUL here */
+ char *coldp; /* can be no match starting before here */
+ char **lastpos; /* [nplus+1] */
+ STATEVARS;
+ states st; /* current states */
+ states fresh; /* states for a fresh start */
+ states tmp; /* temporary */
+ states empty; /* empty set of states */
+};
+
+/* ========= begin header generated by ./mkh ========= */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* === engine.c === */
+static int matcher __P((struct re_guts *g, char *string, size_t nmatch, regmatch_t pmatch[], int eflags));
+static char *dissect __P((struct match *m, char *start, char *stop, sopno startst, sopno stopst));
+static char *backref __P((struct match *m, char *start, char *stop, sopno startst, sopno stopst, sopno lev));
+static char *fast __P((struct match *m, char *start, char *stop, sopno startst, sopno stopst));
+static char *slow __P((struct match *m, char *start, char *stop, sopno startst, sopno stopst));
+static states step __P((struct re_guts *g, sopno start, sopno stop, states bef, int ch, states aft));
+#define BOL (OUT+1)
+#define EOL (BOL+1)
+#define BOLEOL (BOL+2)
+#define NOTHING (BOL+3)
+#define BOW (BOL+4)
+#define EOW (BOL+5)
+#define CODEMAX (BOL+5) /* highest code used */
+#define NONCHAR(c) ((c) > CHAR_MAX)
+#define NNONCHAR (CODEMAX-CHAR_MAX)
+#ifdef REDEBUG
+static void print __P((struct match *m, char *caption, states st, int ch, FILE *d));
+#endif
+#ifdef REDEBUG
+static void at __P((struct match *m, char *title, char *start, char *stop, sopno startst, sopno stopst));
+#endif
+#ifdef REDEBUG
+static char *pchar __P((int ch));
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+/* ========= end header generated by ./mkh ========= */
+
+#ifdef REDEBUG
+#define SP(t, s, c) print(m, t, s, c, stdout)
+#define AT(t, p1, p2, s1, s2) at(m, t, p1, p2, s1, s2)
+#define NOTE(str) { if (m->eflags&REG_TRACE) printf("=%s\n", (str)); }
+#else
+#define SP(t, s, c) /* nothing */
+#define AT(t, p1, p2, s1, s2) /* nothing */
+#define NOTE(s) /* nothing */
+#endif
+
+/*
+ - matcher - the actual matching engine
+ == static int matcher(register struct re_guts *g, char *string, \
+ == size_t nmatch, regmatch_t pmatch[], int eflags);
+ */
+static int /* 0 success, REG_NOMATCH failure */
+matcher(struct re_guts *g, char *string, size_t nmatch, regmatch_t pmatch[], int eflags)
+{
+ register char *endp;
+ register int i;
+ struct match mv;
+ register struct match *m = &mv;
+ register char *dp;
+ const register sopno gf = g->firststate+1; /* +1 for OEND */
+ const register sopno gl = g->laststate;
+ char *start;
+ char *stop;
+
+ /* simplify the situation where possible */
+ if (g->cflags&REG_NOSUB)
+ nmatch = 0;
+ if (eflags&REG_STARTEND) {
+ start = string + pmatch[0].rm_so;
+ stop = string + pmatch[0].rm_eo;
+ } else {
+ start = string;
+ stop = start + strlen(start);
+ }
+ if (stop < start)
+ return(REG_INVARG);
+
+ /* prescreening; this does wonders for this rather slow code */
+ if (g->must != NULL) {
+ for (dp = start; dp < stop; dp++)
+ if (*dp == g->must[0] && stop - dp >= g->mlen &&
+ memcmp(dp, g->must, (size_t)g->mlen) == 0)
+ break;
+ if (dp == stop) /* we didn't find g->must */
+ return(REG_NOMATCH);
+ }
+
+ /* match struct setup */
+ m->g = g;
+ m->eflags = eflags;
+ m->pmatch = NULL;
+ m->lastpos = NULL;
+ m->offp = string;
+ m->beginp = start;
+ m->endp = stop;
+ STATESETUP(m, 4);
+ SETUP(m->st);
+ SETUP(m->fresh);
+ SETUP(m->tmp);
+ SETUP(m->empty);
+ CLEAR(m->empty);
+
+ /* this loop does only one repetition except for backrefs */
+ for (;;) {
+ endp = fast(m, start, stop, gf, gl);
+ if (endp == NULL) { /* a miss */
+ STATETEARDOWN(m);
+ return(REG_NOMATCH);
+ }
+ if (nmatch == 0 && !g->backrefs)
+ break; /* no further info needed */
+
+ /* where? */
+ assert(m->coldp != NULL);
+ for (;;) {
+ NOTE("finding start");
+ endp = slow(m, m->coldp, stop, gf, gl);
+ if (endp != NULL)
+ break;
+ assert(m->coldp < m->endp);
+ m->coldp++;
+ }
+ if (nmatch == 1 && !g->backrefs)
+ break; /* no further info needed */
+
+ /* oh my, he wants the subexpressions... */
+ if (m->pmatch == NULL)
+ m->pmatch = (regmatch_t *)malloc((m->g->nsub + 1) *
+ sizeof(regmatch_t));
+ if (m->pmatch == NULL) {
+ STATETEARDOWN(m);
+ return(REG_ESPACE);
+ }
+ for (i = 1; i <= m->g->nsub; i++)
+ m->pmatch[i].rm_so = m->pmatch[i].rm_eo = -1;
+ if (!g->backrefs && !(m->eflags&REG_BACKR)) {
+ NOTE("dissecting");
+ dp = dissect(m, m->coldp, endp, gf, gl);
+ } else {
+ if (g->nplus > 0 && m->lastpos == NULL)
+ m->lastpos = (char **)malloc((g->nplus+1) *
+ sizeof(char *));
+ if (g->nplus > 0 && m->lastpos == NULL) {
+ free(m->pmatch);
+ STATETEARDOWN(m);
+ return(REG_ESPACE);
+ }
+ NOTE("backref dissect");
+ dp = backref(m, m->coldp, endp, gf, gl, (sopno)0);
+ }
+ if (dp != NULL)
+ break;
+
+ /* uh-oh... we couldn't find a subexpression-level match */
+ assert(g->backrefs); /* must be back references doing it */
+ assert(g->nplus == 0 || m->lastpos != NULL);
+ for (;;) {
+ if (dp != NULL || endp <= m->coldp)
+ break; /* defeat */
+ NOTE("backoff");
+ endp = slow(m, m->coldp, endp-1, gf, gl);
+ if (endp == NULL)
+ break; /* defeat */
+ /* try it on a shorter possibility */
+#ifndef NDEBUG
+ for (i = 1; i <= m->g->nsub; i++) {
+ assert(m->pmatch[i].rm_so == -1);
+ assert(m->pmatch[i].rm_eo == -1);
+ }
+#endif
+ NOTE("backoff dissect");
+ dp = backref(m, m->coldp, endp, gf, gl, (sopno)0);
+ }
+ assert(dp == NULL || dp == endp);
+ if (dp != NULL) /* found a shorter one */
+ break;
+
+ /* despite initial appearances, there is no match here */
+ NOTE("false alarm");
+ start = m->coldp + 1; /* recycle starting later */
+ assert(start <= stop);
+ }
+
+ /* fill in the details if requested */
+ if (nmatch > 0) {
+ pmatch[0].rm_so = m->coldp - m->offp;
+ pmatch[0].rm_eo = endp - m->offp;
+ }
+ if (nmatch > 1) {
+ assert(m->pmatch != NULL);
+ for (i = 1; i < nmatch; i++)
+ if (i <= m->g->nsub)
+ pmatch[i] = m->pmatch[i];
+ else {
+ pmatch[i].rm_so = -1;
+ pmatch[i].rm_eo = -1;
+ }
+ }
+
+ if (m->pmatch != NULL)
+ free((char *)m->pmatch);
+ if (m->lastpos != NULL)
+ free((char *)m->lastpos);
+ STATETEARDOWN(m);
+ return(0);
+}
+
+/*
+ - dissect - figure out what matched what, no back references
+ == static char *dissect(register struct match *m, char *start, \
+ == char *stop, sopno startst, sopno stopst);
+ */
+static char * /* == stop (success) always */
+dissect(struct match *m, char *start, char *stop, sopno startst, sopno stopst)
+{
+ register int i;
+ register sopno ss; /* start sop of current subRE */
+ register sopno es; /* end sop of current subRE */
+ register char *sp; /* start of string matched by it */
+ register char *stp; /* string matched by it cannot pass here */
+ register char *rest; /* start of rest of string */
+ register char *tail; /* string unmatched by rest of RE */
+ register sopno ssub; /* start sop of subsubRE */
+ register sopno esub; /* end sop of subsubRE */
+ register char *ssp; /* start of string matched by subsubRE */
+ register char *sep; /* end of string matched by subsubRE */
+ register char *oldssp; /* previous ssp */
+ register char *dp;
+
+ AT("diss", start, stop, startst, stopst);
+ sp = start;
+ for (ss = startst; ss < stopst; ss = es) {
+ /* identify end of subRE */
+ es = ss;
+ switch (OP(m->g->strip[es])) {
+ case OPLUS_:
+ case OQUEST_:
+ es += OPND(m->g->strip[es]);
+ break;
+ case OCH_:
+ while (OP(m->g->strip[es]) != O_CH)
+ es += OPND(m->g->strip[es]);
+ break;
+ }
+ es++;
+
+ /* figure out what it matched */
+ switch (OP(m->g->strip[ss])) {
+ case OEND:
+ assert(nope);
+ break;
+ case OCHAR:
+ sp++;
+ break;
+ case OBOL:
+ case OEOL:
+ case OBOW:
+ case OEOW:
+ break;
+ case OANY:
+ case OANYOF:
+ sp++;
+ break;
+ case OBACK_:
+ case O_BACK:
+ assert(nope);
+ break;
+ /* cases where length of match is hard to find */
+ case OQUEST_:
+ stp = stop;
+ for (;;) {
+ /* how long could this one be? */
+ rest = slow(m, sp, stp, ss, es);
+ assert(rest != NULL); /* it did match */
+ /* could the rest match the rest? */
+ tail = slow(m, rest, stop, es, stopst);
+ if (tail == stop)
+ break; /* yes! */
+ /* no -- try a shorter match for this one */
+ stp = rest - 1;
+ assert(stp >= sp); /* it did work */
+ }
+ ssub = ss + 1;
+ esub = es - 1;
+ /* did innards match? */
+ if (slow(m, sp, rest, ssub, esub) != NULL) {
+ dp = dissect(m, sp, rest, ssub, esub);
+ assert(dp == rest);
+ } else /* no */
+ assert(sp == rest);
+ sp = rest;
+ break;
+ case OPLUS_:
+ stp = stop;
+ for (;;) {
+ /* how long could this one be? */
+ rest = slow(m, sp, stp, ss, es);
+ assert(rest != NULL); /* it did match */
+ /* could the rest match the rest? */
+ tail = slow(m, rest, stop, es, stopst);
+ if (tail == stop)
+ break; /* yes! */
+ /* no -- try a shorter match for this one */
+ stp = rest - 1;
+ assert(stp >= sp); /* it did work */
+ }
+ ssub = ss + 1;
+ esub = es - 1;
+ ssp = sp;
+ oldssp = ssp;
+ for (;;) { /* find last match of innards */
+ sep = slow(m, ssp, rest, ssub, esub);
+ if (sep == NULL || sep == ssp)
+ break; /* failed or matched null */
+ oldssp = ssp; /* on to next try */
+ ssp = sep;
+ }
+ if (sep == NULL) {
+ /* last successful match */
+ sep = ssp;
+ ssp = oldssp;
+ }
+ assert(sep == rest); /* must exhaust substring */
+ assert(slow(m, ssp, sep, ssub, esub) == rest);
+ dp = dissect(m, ssp, sep, ssub, esub);
+ assert(dp == sep);
+ sp = rest;
+ break;
+ case OCH_:
+ stp = stop;
+ for (;;) {
+ /* how long could this one be? */
+ rest = slow(m, sp, stp, ss, es);
+ assert(rest != NULL); /* it did match */
+ /* could the rest match the rest? */
+ tail = slow(m, rest, stop, es, stopst);
+ if (tail == stop)
+ break; /* yes! */
+ /* no -- try a shorter match for this one */
+ stp = rest - 1;
+ assert(stp >= sp); /* it did work */
+ }
+ ssub = ss + 1;
+ esub = ss + OPND(m->g->strip[ss]) - 1;
+ assert(OP(m->g->strip[esub]) == OOR1);
+ for (;;) { /* find first matching branch */
+ if (slow(m, sp, rest, ssub, esub) == rest)
+ break; /* it matched all of it */
+ /* that one missed, try next one */
+ assert(OP(m->g->strip[esub]) == OOR1);
+ esub++;
+ assert(OP(m->g->strip[esub]) == OOR2);
+ ssub = esub + 1;
+ esub += OPND(m->g->strip[esub]);
+ if (OP(m->g->strip[esub]) == OOR2)
+ esub--;
+ else
+ assert(OP(m->g->strip[esub]) == O_CH);
+ }
+ dp = dissect(m, sp, rest, ssub, esub);
+ assert(dp == rest);
+ sp = rest;
+ break;
+ case O_PLUS:
+ case O_QUEST:
+ case OOR1:
+ case OOR2:
+ case O_CH:
+ assert(nope);
+ break;
+ case OLPAREN:
+ i = OPND(m->g->strip[ss]);
+ assert(0 < i && i <= m->g->nsub);
+ m->pmatch[i].rm_so = sp - m->offp;
+ break;
+ case ORPAREN:
+ i = OPND(m->g->strip[ss]);
+ assert(0 < i && i <= m->g->nsub);
+ m->pmatch[i].rm_eo = sp - m->offp;
+ break;
+ default: /* uh oh */
+ assert(nope);
+ break;
+ }
+ }
+
+ assert(sp == stop);
+ return(sp);
+}
+
+/*
+ - backref - figure out what matched what, figuring in back references
+ == static char *backref(register struct match *m, char *start, \
+ == char *stop, sopno startst, sopno stopst, sopno lev);
+ */
+static char * /* == stop (success) or NULL (failure) */
+backref(struct match *m, char *start, char *stop, sopno startst, sopno stopst, sopno lev)
+{
+ register int i;
+ register sopno ss; /* start sop of current subRE */
+ register char *sp; /* start of string matched by it */
+ register sopno ssub; /* start sop of subsubRE */
+ register sopno esub; /* end sop of subsubRE */
+ register char *ssp; /* start of string matched by subsubRE */
+ register char *dp;
+ register size_t len;
+ register int hard;
+ register sop s;
+ register regoff_t offsave;
+ register cset *cs;
+
+ AT("back", start, stop, startst, stopst);
+ sp = start;
+
+ /* get as far as we can with easy stuff */
+ hard = 0;
+ for (ss = startst; !hard && ss < stopst; ss++)
+ switch (OP(s = m->g->strip[ss])) {
+ case OCHAR:
+ if (sp == stop || *sp++ != (char)OPND(s))
+ return(NULL);
+ break;
+ case OANY:
+ if (sp == stop)
+ return(NULL);
+ sp++;
+ break;
+ case OANYOF:
+ cs = &m->g->sets[OPND(s)];
+ if (sp == stop || !CHIN(cs, *sp++))
+ return(NULL);
+ break;
+ case OBOL:
+ if ( (sp == m->beginp && !(m->eflags&REG_NOTBOL)) ||
+ (sp < m->endp && *(sp-1) == '\n' &&
+ (m->g->cflags&REG_NEWLINE)) )
+ { /* yes */ }
+ else
+ return(NULL);
+ break;
+ case OEOL:
+ if ( (sp == m->endp && !(m->eflags&REG_NOTEOL)) ||
+ (sp < m->endp && *sp == '\n' &&
+ (m->g->cflags&REG_NEWLINE)) )
+ { /* yes */ }
+ else
+ return(NULL);
+ break;
+ case OBOW:
+ if (( (sp == m->beginp && !(m->eflags&REG_NOTBOL)) ||
+ (sp < m->endp && *(sp-1) == '\n' &&
+ (m->g->cflags&REG_NEWLINE)) ||
+ (sp > m->beginp &&
+ !ISWORD(*(sp-1))) ) &&
+ (sp < m->endp && ISWORD(*sp)) )
+ { /* yes */ }
+ else
+ return(NULL);
+ break;
+ case OEOW:
+ if (( (sp == m->endp && !(m->eflags&REG_NOTEOL)) ||
+ (sp < m->endp && *sp == '\n' &&
+ (m->g->cflags&REG_NEWLINE)) ||
+ (sp < m->endp && !ISWORD(*sp)) ) &&
+ (sp > m->beginp && ISWORD(*(sp-1))) )
+ { /* yes */ }
+ else
+ return(NULL);
+ break;
+ case O_QUEST:
+ break;
+ case OOR1: /* matches null but needs to skip */
+ ss++;
+ s = m->g->strip[ss];
+ do {
+ assert(OP(s) == OOR2);
+ ss += OPND(s);
+ } while (OP(s = m->g->strip[ss]) != O_CH);
+ /* note that the ss++ gets us past the O_CH */
+ break;
+ default: /* have to make a choice */
+ hard = 1;
+ break;
+ }
+ if (!hard) { /* that was it! */
+ if (sp != stop)
+ return(NULL);
+ return(sp);
+ }
+ ss--; /* adjust for the for's final increment */
+
+ /* the hard stuff */
+ AT("hard", sp, stop, ss, stopst);
+ s = m->g->strip[ss];
+ switch (OP(s)) {
+ case OBACK_: /* the vilest depths */
+ i = OPND(s);
+ assert(0 < i && i <= m->g->nsub);
+ if (m->pmatch[i].rm_eo == -1)
+ return(NULL);
+ assert(m->pmatch[i].rm_so != -1);
+ len = m->pmatch[i].rm_eo - m->pmatch[i].rm_so;
+ assert(stop - m->beginp >= len);
+ if (sp > stop - len)
+ return(NULL); /* not enough left to match */
+ ssp = m->offp + m->pmatch[i].rm_so;
+ if (memcmp(sp, ssp, len) != 0)
+ return(NULL);
+ while (m->g->strip[ss] != SOP(O_BACK, i))
+ ss++;
+ return(backref(m, sp+len, stop, ss+1, stopst, lev));
+ break;
+ case OQUEST_: /* to null or not */
+ dp = backref(m, sp, stop, ss+1, stopst, lev);
+ if (dp != NULL)
+ return(dp); /* not */
+ return(backref(m, sp, stop, ss+OPND(s)+1, stopst, lev));
+ break;
+ case OPLUS_:
+ assert(m->lastpos != NULL);
+ assert(lev+1 <= m->g->nplus);
+ m->lastpos[lev+1] = sp;
+ return(backref(m, sp, stop, ss+1, stopst, lev+1));
+ break;
+ case O_PLUS:
+ if (sp == m->lastpos[lev]) /* last pass matched null */
+ return(backref(m, sp, stop, ss+1, stopst, lev-1));
+ /* try another pass */
+ m->lastpos[lev] = sp;
+ dp = backref(m, sp, stop, ss-OPND(s)+1, stopst, lev);
+ if (dp == NULL)
+ return(backref(m, sp, stop, ss+1, stopst, lev-1));
+ else
+ return(dp);
+ break;
+ case OCH_: /* find the right one, if any */
+ ssub = ss + 1;
+ esub = ss + OPND(s) - 1;
+ assert(OP(m->g->strip[esub]) == OOR1);
+ for (;;) { /* find first matching branch */
+ dp = backref(m, sp, stop, ssub, esub, lev);
+ if (dp != NULL)
+ return(dp);
+ /* that one missed, try next one */
+ if (OP(m->g->strip[esub]) == O_CH)
+ return(NULL); /* there is none */
+ esub++;
+ assert(OP(m->g->strip[esub]) == OOR2);
+ ssub = esub + 1;
+ esub += OPND(m->g->strip[esub]);
+ if (OP(m->g->strip[esub]) == OOR2)
+ esub--;
+ else
+ assert(OP(m->g->strip[esub]) == O_CH);
+ }
+ break;
+ case OLPAREN: /* must undo assignment if rest fails */
+ i = OPND(s);
+ assert(0 < i && i <= m->g->nsub);
+ offsave = m->pmatch[i].rm_so;
+ m->pmatch[i].rm_so = sp - m->offp;
+ dp = backref(m, sp, stop, ss+1, stopst, lev);
+ if (dp != NULL)
+ return(dp);
+ m->pmatch[i].rm_so = offsave;
+ return(NULL);
+ break;
+ case ORPAREN: /* must undo assignment if rest fails */
+ i = OPND(s);
+ assert(0 < i && i <= m->g->nsub);
+ offsave = m->pmatch[i].rm_eo;
+ m->pmatch[i].rm_eo = sp - m->offp;
+ dp = backref(m, sp, stop, ss+1, stopst, lev);
+ if (dp != NULL)
+ return(dp);
+ m->pmatch[i].rm_eo = offsave;
+ return(NULL);
+ break;
+ default: /* uh oh */
+ assert(nope);
+ break;
+ }
+
+ /* "can't happen" */
+ assert(nope);
+ /* NOTREACHED */
+ return(NULL);
+}
+
+/*
+ - fast - step through the string at top speed
+ == static char *fast(register struct match *m, char *start, \
+ == char *stop, sopno startst, sopno stopst);
+ */
+static char * /* where tentative match ended, or NULL */
+fast(struct match *m, char *start, char *stop, sopno startst, sopno stopst)
+{
+ register states st = m->st;
+ register states fresh = m->fresh;
+ register states tmp = m->tmp;
+ register char *p = start;
+ register int c = (start == m->beginp) ? OUT : *(start-1);
+ register int lastc; /* previous c */
+ register int flagch;
+ register int i;
+ register char *coldp; /* last p after which no match was underway */
+
+ CLEAR(st);
+ SET1(st, startst);
+ st = step(m->g, startst, stopst, st, NOTHING, st);
+ ASSIGN(fresh, st);
+ SP("start", st, *p);
+ coldp = NULL;
+ for (;;) {
+ /* next character */
+ lastc = c;
+ c = (p == m->endp) ? OUT : *p;
+ if (EQ(st, fresh))
+ coldp = p;
+
+ /* is there an EOL and/or BOL between lastc and c? */
+ flagch = '\0';
+ i = 0;
+ if ( (lastc == '\n' && m->g->cflags&REG_NEWLINE) ||
+ (lastc == OUT && !(m->eflags&REG_NOTBOL)) ) {
+ flagch = BOL;
+ i = m->g->nbol;
+ }
+ if ( (c == '\n' && m->g->cflags&REG_NEWLINE) ||
+ (c == OUT && !(m->eflags&REG_NOTEOL)) ) {
+ flagch = (flagch == BOL) ? BOLEOL : EOL;
+ i += m->g->neol;
+ }
+ if (i != 0) {
+ for (; i > 0; i--)
+ st = step(m->g, startst, stopst, st, flagch, st);
+ SP("boleol", st, c);
+ }
+
+ /* how about a word boundary? */
+ if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) &&
+ (c != OUT && ISWORD(c)) ) {
+ flagch = BOW;
+ }
+ if ( (lastc != OUT && ISWORD(lastc)) &&
+ (flagch == EOL || (c != OUT && !ISWORD(c))) ) {
+ flagch = EOW;
+ }
+ if (flagch == BOW || flagch == EOW) {
+ st = step(m->g, startst, stopst, st, flagch, st);
+ SP("boweow", st, c);
+ }
+
+ /* are we done? */
+ if (ISSET(st, stopst) || p == stop)
+ break; /* NOTE BREAK OUT */
+
+ /* no, we must deal with this character */
+ ASSIGN(tmp, st);
+ ASSIGN(st, fresh);
+ assert(c != OUT);
+ st = step(m->g, startst, stopst, tmp, c, st);
+ SP("aft", st, c);
+ assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st));
+ p++;
+ }
+
+ assert(coldp != NULL);
+ m->coldp = coldp;
+ if (ISSET(st, stopst))
+ return(p+1);
+ else
+ return(NULL);
+}
+
+/*
+ - slow - step through the string more deliberately
+ == static char *slow(register struct match *m, char *start, \
+ == char *stop, sopno startst, sopno stopst);
+ */
+static char * /* where it ended */
+slow(struct match *m, char *start, char *stop, sopno startst, sopno stopst)
+{
+ register states st = m->st;
+ register states empty = m->empty;
+ register states tmp = m->tmp;
+ register char *p = start;
+ register int c = (start == m->beginp) ? OUT : *(start-1);
+ register int lastc; /* previous c */
+ register int flagch;
+ register int i;
+ register char *matchp; /* last p at which a match ended */
+
+ AT("slow", start, stop, startst, stopst);
+ CLEAR(st);
+ SET1(st, startst);
+ SP("sstart", st, *p);
+ st = step(m->g, startst, stopst, st, NOTHING, st);
+ matchp = NULL;
+ for (;;) {
+ /* next character */
+ lastc = c;
+ c = (p == m->endp) ? OUT : *p;
+
+ /* is there an EOL and/or BOL between lastc and c? */
+ flagch = '\0';
+ i = 0;
+ if ( (lastc == '\n' && m->g->cflags&REG_NEWLINE) ||
+ (lastc == OUT && !(m->eflags&REG_NOTBOL)) ) {
+ flagch = BOL;
+ i = m->g->nbol;
+ }
+ if ( (c == '\n' && m->g->cflags&REG_NEWLINE) ||
+ (c == OUT && !(m->eflags&REG_NOTEOL)) ) {
+ flagch = (flagch == BOL) ? BOLEOL : EOL;
+ i += m->g->neol;
+ }
+ if (i != 0) {
+ for (; i > 0; i--)
+ st = step(m->g, startst, stopst, st, flagch, st);
+ SP("sboleol", st, c);
+ }
+
+ /* how about a word boundary? */
+ if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) &&
+ (c != OUT && ISWORD(c)) ) {
+ flagch = BOW;
+ }
+ if ( (lastc != OUT && ISWORD(lastc)) &&
+ (flagch == EOL || (c != OUT && !ISWORD(c))) ) {
+ flagch = EOW;
+ }
+ if (flagch == BOW || flagch == EOW) {
+ st = step(m->g, startst, stopst, st, flagch, st);
+ SP("sboweow", st, c);
+ }
+
+ /* are we done? */
+ if (ISSET(st, stopst))
+ matchp = p;
+ if (EQ(st, empty) || p == stop)
+ break; /* NOTE BREAK OUT */
+
+ /* no, we must deal with this character */
+ ASSIGN(tmp, st);
+ ASSIGN(st, empty);
+ assert(c != OUT);
+ st = step(m->g, startst, stopst, tmp, c, st);
+ SP("saft", st, c);
+ assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st));
+ p++;
+ }
+
+ return(matchp);
+}
+
+
+/*
+ - step - map set of states reachable before char to set reachable after
+ == static states step(register struct re_guts *g, sopno start, sopno stop, \
+ == register states bef, int ch, register states aft);
+ == #define BOL (OUT+1)
+ == #define EOL (BOL+1)
+ == #define BOLEOL (BOL+2)
+ == #define NOTHING (BOL+3)
+ == #define BOW (BOL+4)
+ == #define EOW (BOL+5)
+ == #define CODEMAX (BOL+5) // highest code used
+ == #define NONCHAR(c) ((c) > CHAR_MAX)
+ == #define NNONCHAR (CODEMAX-CHAR_MAX)
+ */
+static states
+step(struct re_guts *g,
+ sopno start, /* start state within strip */
+ sopno stop, /* state after stop state within strip */
+ states bef, /* states reachable before */
+ int ch, /* character or NONCHAR code */
+ states aft) /* states already known reachable after */
+{
+ register cset *cs;
+ register sop s;
+ register sopno pc;
+ register onestate here; /* note, macros know this name */
+ register sopno look;
+ register int i;
+
+ for (pc = start, INIT(here, pc); pc != stop; pc++, INC(here)) {
+ s = g->strip[pc];
+ switch (OP(s)) {
+ case OEND:
+ assert(pc == stop-1);
+ break;
+ case OCHAR:
+ /* only characters can match */
+ assert(!NONCHAR(ch) || ch != (char)OPND(s));
+ if (ch == (char)OPND(s))
+ FWD(aft, bef, 1);
+ break;
+ case OBOL:
+ if (ch == BOL || ch == BOLEOL)
+ FWD(aft, bef, 1);
+ break;
+ case OEOL:
+ if (ch == EOL || ch == BOLEOL)
+ FWD(aft, bef, 1);
+ break;
+ case OBOW:
+ if (ch == BOW)
+ FWD(aft, bef, 1);
+ break;
+ case OEOW:
+ if (ch == EOW)
+ FWD(aft, bef, 1);
+ break;
+ case OANY:
+ if (!NONCHAR(ch))
+ FWD(aft, bef, 1);
+ break;
+ case OANYOF:
+ cs = &g->sets[OPND(s)];
+ if (!NONCHAR(ch) && CHIN(cs, ch))
+ FWD(aft, bef, 1);
+ break;
+ case OBACK_: /* ignored here */
+ case O_BACK:
+ FWD(aft, aft, 1);
+ break;
+ case OPLUS_: /* forward, this is just an empty */
+ FWD(aft, aft, 1);
+ break;
+ case O_PLUS: /* both forward and back */
+ FWD(aft, aft, 1);
+ i = ISSETBACK(aft, OPND(s));
+ BACK(aft, aft, OPND(s));
+ if (!i && ISSETBACK(aft, OPND(s))) {
+ /* oho, must reconsider loop body */
+ pc -= OPND(s) + 1;
+ INIT(here, pc);
+ }
+ break;
+ case OQUEST_: /* two branches, both forward */
+ FWD(aft, aft, 1);
+ FWD(aft, aft, OPND(s));
+ break;
+ case O_QUEST: /* just an empty */
+ FWD(aft, aft, 1);
+ break;
+ case OLPAREN: /* not significant here */
+ case ORPAREN:
+ FWD(aft, aft, 1);
+ break;
+ case OCH_: /* mark the first two branches */
+ FWD(aft, aft, 1);
+ assert(OP(g->strip[pc+OPND(s)]) == OOR2);
+ FWD(aft, aft, OPND(s));
+ break;
+ case OOR1: /* done a branch, find the O_CH */
+ if (ISSTATEIN(aft, here)) {
+ for (look = 1;
+ OP(s = g->strip[pc+look]) != O_CH;
+ look += OPND(s))
+ assert(OP(s) == OOR2);
+ FWD(aft, aft, look);
+ }
+ break;
+ case OOR2: /* propagate OCH_'s marking */
+ FWD(aft, aft, 1);
+ if (OP(g->strip[pc+OPND(s)]) != O_CH) {
+ assert(OP(g->strip[pc+OPND(s)]) == OOR2);
+ FWD(aft, aft, OPND(s));
+ }
+ break;
+ case O_CH: /* just empty */
+ FWD(aft, aft, 1);
+ break;
+ default: /* ooooops... */
+ assert(nope);
+ break;
+ }
+ }
+
+ return(aft);
+}
+
+#ifdef REDEBUG
+/*
+ - print - print a set of states
+ == #ifdef REDEBUG
+ == static void print(struct match *m, char *caption, states st, \
+ == int ch, FILE *d);
+ == #endif
+ */
+static void
+print(struct match *m, char *caption, states st, int ch, FILE *d)
+{
+ register struct re_guts *g = m->g;
+ register int i;
+ register int first = 1;
+
+ if (!(m->eflags&REG_TRACE))
+ return;
+
+ fprintf(d, "%s", caption);
+ if (ch != '\0')
+ fprintf(d, " %s", pchar(ch));
+ for (i = 0; i < g->nstates; i++)
+ if (ISSET(st, i)) {
+ fprintf(d, "%s%d", (first) ? "\t" : ", ", i);
+ first = 0;
+ }
+ fprintf(d, "\n");
+}
+
+/*
+ - at - print current situation
+ == #ifdef REDEBUG
+ == static void at(struct match *m, char *title, char *start, char *stop, \
+ == sopno startst, sopno stopst);
+ == #endif
+ */
+static void
+at(struct match *m, char *title, char *start, char *stop, sopno startst, sopno stopst)
+{
+ if (!(m->eflags&REG_TRACE))
+ return;
+
+ printf("%s %s-", title, pchar(*start));
+ printf("%s ", pchar(*stop));
+ printf("%ld-%ld\n", (long)startst, (long)stopst);
+}
+
+#ifndef PCHARDONE
+#define PCHARDONE /* never again */
+/*
+ - pchar - make a character printable
+ == #ifdef REDEBUG
+ == static char *pchar(int ch);
+ == #endif
+ *
+ * Is this identical to regchar() over in debug.c? Well, yes. But a
+ * duplicate here avoids having a debugging-capable regexec.o tied to
+ * a matching debug.o, and this is convenient. It all disappears in
+ * the non-debug compilation anyway, so it doesn't matter much.
+ */
+static char * /* -> representation */
+pchar(int ch)
+{
+ static char pbuf[10];
+
+ if (isprint(ch) || ch == ' ')
+ sprintf(pbuf, "%c", ch);
+ else
+ sprintf(pbuf, "\\%o", ch);
+ return(pbuf);
+}
+#endif
+#endif
+
+#undef matcher
+#undef fast
+#undef slow
+#undef dissect
+#undef backref
+#undef step
+#undef print
+#undef at
+#undef match
generated by cgit v1.2.3-70-g09d2 (git 2.47.0) at 2024-11-22 13:41:54 +0000