static void
makedfa(nfagrammar *gr, nfa *nf, dfa *d)
{
int nbits = nf->nf_nstates;
bitset ss;
int xx_nstates;
ss_state *xx_state, *yy;
ss_arc *zz;
int istate, jstate, iarc, jarc, ibit;
nfastate *st;
nfaarc *ar;
ss = newbitset(nbits);
addclosure(ss, nf, nf->nf_start);
xx_state = (ss_state *)PyObject_MALLOC(sizeof(ss_state));
if (xx_state == NULL)
Py_FatalError("no mem for xx_state in makedfa");
xx_nstates = 1;
yy = &xx_state[0];
yy->ss_ss = ss;
yy->ss_narcs = 0;
yy->ss_arc = NULL;
yy->ss_deleted = 0;
yy->ss_finish = testbit(ss, nf->nf_finish);
if (yy->ss_finish)
printf("Error: nonterminal '%s' may produce empty.\n",
nf->nf_name);
/* This algorithm is from a book written before
the invention of structured programming... */
/* For each unmarked state... */
for (istate = 0; istate < xx_nstates; ++istate) {
size_t size;
yy = &xx_state[istate];
ss = yy->ss_ss;
/* For all its states... */
for (ibit = 0; ibit < nf->nf_nstates; ++ibit) {
if (!testbit(ss, ibit))
continue;
st = &nf->nf_state[ibit];
/* For all non-empty arcs from this state... */
for (iarc = 0; iarc < st->st_narcs; iarc++) {
ar = &st->st_arc[iarc];
if (ar->ar_label == EMPTY)
continue;
/* Look up in list of arcs from this state */
for (jarc = 0; jarc < yy->ss_narcs; ++jarc) {
zz = &yy->ss_arc[jarc];
if (ar->ar_label == zz->sa_label)
goto found;
}
/* Add new arc for this state */
size = sizeof(ss_arc) * (yy->ss_narcs + 1);
yy->ss_arc = (ss_arc *)PyObject_REALLOC(
yy->ss_arc, size);
if (yy->ss_arc == NULL)
Py_FatalError("out of mem");
zz = &yy->ss_arc[yy->ss_narcs++];
zz->sa_label = ar->ar_label;
zz->sa_bitset = newbitset(nbits);
zz->sa_arrow = -1;
found: ;
/* Add destination */
addclosure(zz->sa_bitset, nf, ar->ar_arrow);
}
}
/* Now look up all the arrow states */
for (jarc = 0; jarc < xx_state[istate].ss_narcs; jarc++) {
zz = &xx_state[istate].ss_arc[jarc];
for (jstate = 0; jstate < xx_nstates; jstate++) {
if (samebitset(zz->sa_bitset,
xx_state[jstate].ss_ss, nbits)) {
zz->sa_arrow = jstate;
goto done;
}
}
size = sizeof(ss_state) * (xx_nstates + 1);
xx_state = (ss_state *)PyObject_REALLOC(xx_state,
size);
if (xx_state == NULL)
Py_FatalError("out of mem");
zz->sa_arrow = xx_nstates;
yy = &xx_state[xx_nstates++];
yy->ss_ss = zz->sa_bitset;
yy->ss_narcs = 0;
yy->ss_arc = NULL;
yy->ss_deleted = 0;
yy->ss_finish = testbit(yy->ss_ss, nf->nf_finish);
done: ;
}
}
if (Py_DebugFlag)
printssdfa(xx_nstates, xx_state, nbits, &gr->gr_ll,
"before minimizing");
simplify(xx_nstates, xx_state);
if (Py_DebugFlag)
printssdfa(xx_nstates, xx_state, nbits, &gr->gr_ll,
"after minimizing");
convert(d, xx_nstates, xx_state);
/* XXX cleanup */
PyObject_FREE(xx_state);
}
static void
calcfirstset(grammar *g, dfa *d)
{
int i, j;
state *s;
arc *a;
int nsyms;
int *sym;
int nbits;
static bitset dummy;
bitset result;
int type;
dfa *d1;
label *l0;
if (Py_DebugFlag)
printf("Calculate FIRST set for '%s'\n", d->d_name);
if (dummy == NULL)
dummy = newbitset(1);
if (d->d_first == dummy) {
fprintf(stderr, "Left-recursion for '%s'\n", d->d_name);
return;
}
if (d->d_first != NULL) {
fprintf(stderr, "Re-calculating FIRST set for '%s' ???\n",
d->d_name);
}
d->d_first = dummy;
l0 = g->g_ll.ll_label;
nbits = g->g_ll.ll_nlabels;
result = newbitset(nbits);
sym = (int *)PyObject_MALLOC(sizeof(int));
if (sym == NULL)
Py_FatalError("no mem for new sym in calcfirstset");
nsyms = 1;
sym[0] = findlabel(&g->g_ll, d->d_type, (char *)NULL);
s = &d->d_state[d->d_initial];
for (i = 0; i < s->s_narcs; i++) {
a = &s->s_arc[i];
for (j = 0; j < nsyms; j++) {
if (sym[j] == a->a_lbl)
break;
}
if (j >= nsyms) { /* New label */
sym = (int *)PyObject_REALLOC(sym,
sizeof(int) * (nsyms + 1));
if (sym == NULL)
Py_FatalError(
"no mem to resize sym in calcfirstset");
sym[nsyms++] = a->a_lbl;
type = l0[a->a_lbl].lb_type;
if (ISNONTERMINAL(type)) {
d1 = PyGrammar_FindDFA(g, type);
if (d1->d_first == dummy) {
fprintf(stderr,
"Left-recursion below '%s'\n",
d->d_name);
}
else {
if (d1->d_first == NULL)
calcfirstset(g, d1);
mergebitset(result,
d1->d_first, nbits);
}
}
else if (ISTERMINAL(type)) {
addbit(result, a->a_lbl);
}
}
}
d->d_first = result;
if (Py_DebugFlag) {
printf("FIRST set for '%s': {", d->d_name);
for (i = 0; i < nbits; i++) {
if (testbit(result, i))
printf(" %s", PyGrammar_LabelRepr(&l0[i]));
}
printf(" }\n");
}
PyObject_FREE(sym);
}
