fa *mkdfa(const char *s, int anchor) /* does the real work of making a dfa */
/* anchor = 1 for anchored matches, else 0 */
{
Node *p, *p1;
fa *f;
p = reparse(s);
p1 = op2(CAT, op2(STAR, op2(ALL, NIL, NIL), NIL), p);
/* put ALL STAR in front of reg. exp. */
p1 = op2(CAT, p1, op2(FINAL, NIL, NIL));
/* put FINAL after reg. exp. */
poscnt = 0;
penter(p1); /* enter parent pointers and leaf indices */
if ((f = (fa *) calloc(1, sizeof(fa) + poscnt*sizeof(rrow))) == NULL)
overflo("out of space for fa");
f->accept = poscnt-1; /* penter has computed number of positions in re */
cfoll(f, p1); /* set up follow sets */
freetr(p1);
if ((f->posns[0] = (int *) calloc(1, *(f->re[0].lfollow)*sizeof(int))) == NULL)
overflo("out of space in makedfa");
if ((f->posns[1] = (int *) calloc(1, sizeof(int))) == NULL)
overflo("out of space in makedfa");
*f->posns[1] = 0;
f->initstat = makeinit(f, anchor);
f->anchor = anchor;
f->restr = (uschar *) tostring(s);
return f;
}
int pmatch(fa *f, const char *p0) /* longest match, for sub */
{
int s, ns;
uschar *p = (uschar *) p0;
uschar *q;
int i, k;
/* s = f->reset ? makeinit(f,1) : f->initstat; */
if (f->reset) {
f->initstat = s = makeinit(f,1);
} else {
s = f->initstat;
}
patbeg = (char *) p;
patlen = -1;
do {
q = p;
do {
if (f->out[s]) /* final state */
patlen = q-p;
/* assert(*q < NCHARS); */
if ((ns = f->gototab[s][*q]) != 0)
s = ns;
else
s = cgoto(f, s, *q);
if (s == 1) { /* no transition */
if (patlen >= 0) {
patbeg = (char *) p;
return(1);
}
else
goto nextin; /* no match */
}
} while (*q++ != 0);
if (f->out[s])
patlen = q-p-1; /* don't count $ */
if (patlen >= 0) {
patbeg = (char *) p;
return(1);
}
nextin:
s = 2;
if (f->reset) {
for (i = 2; i <= f->curstat; i++)
xfree(f->posns[i]);
k = *f->posns[0];
if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL)
overflo("out of space in pmatch");
for (i = 0; i <= k; i++)
(f->posns[2])[i] = (f->posns[0])[i];
f->initstat = f->curstat = 2;
f->out[2] = f->out[0];
for (i = 0; i < NCHARS; i++)
f->gototab[2][i] = 0;
}
} while (*p++ != 0);
return (0);
}
int nematch(fa *f, char *p0) /* non-empty match, for sub */
{
int s, ns;
uschar *p = (uschar *) p0;
uschar *q;
int i, k;
s = f->reset ? makeinit(f,1) : f->initstat;
patlen = -1;
while (*p) {
q = p;
do {
if (f->out[s]) /* final state */
patlen = q-p;
if ((ns = f->gototab[s][*q]) != 0)
s = ns;
else
s = cgoto(f, s, *q);
if (s == 1) /* no transition */
if (patlen > 0) {
patbeg = (char *) p;
return(1);
} else
goto nnextin; /* no nonempty match */
} while (*q++ != 0);
if (f->out[s])
patlen = q-p-1; /* don't count $ */
if (patlen > 0 ) {
patbeg = (char *) p;
return(1);
}
nnextin:
s = 2;
if (f->reset) {
for (i = 2; i <= f->curstat; i++)
xfree(f->posns[i]);
k = *f->posns[0];
if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL)
overflo("out of state space");
for (i = 0; i <= k; i++)
(f->posns[2])[i] = (f->posns[0])[i];
f->initstat = f->curstat = 2;
f->out[2] = f->out[0];
for (i = 0; i < NCHARS; i++)
f->gototab[2][i] = 0;
}
p++;
}
return (0);
}
int match(fa *f, char *p0) /* shortest match ? */
{
int s, ns;
uschar *p = (uschar *) p0;
s = f->reset ? makeinit(f,0) : f->initstat;
if (f->out[s])
return(1);
do {
if ((ns = f->gototab[s][*p]) != 0)
s = ns;
else
s = cgoto(f, s, *p);
if (f->out[s])
return(1);
} while (*p++ != 0);
return(0);
}
