Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
/* If the start symbol isn't useful, then nothing will be useful. */
- if (!BITISSET (N, start_symbol - ntokens))
- goto end_iteration;
-
- SETBIT (V, start_symbol);
-
- while (1)
+ if (BITISSET (N, start_symbol - ntokens))
{
- for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
- Vp[i] = V[i];
- for (i = 1; i <= nrules; i++)
+ SETBIT (V, start_symbol);
+
+ while (1)
{
- if (!BITISSET (Pp, i) && BITISSET (P, i) && BITISSET (V, rule_table[i].lhs))
+ for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
+ Vp[i] = V[i];
+ for (i = 1; i <= nrules; i++)
{
- for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
+ if (!BITISSET (Pp, i)
+ && BITISSET (P, i)
+ && BITISSET (V, rule_table[i].lhs))
{
- if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
- {
+ for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
+ if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
SETBIT (Vp, t);
- }
+ SETBIT (Pp, i);
}
- SETBIT (Pp, i);
}
+ if (bits_equal (V, Vp, WORDSIZE (nsyms)))
+ break;
+ Vs = Vp;
+ Vp = V;
+ V = Vs;
}
- if (bits_equal (V, Vp, WORDSIZE (nsyms)))
- {
- break;
- }
- Vs = Vp;
- Vp = V;
- V = Vs;
}
-end_iteration:
XFREE (V);
V = Vp;
fprintf (out, _("Useless rules:"));
fprintf (out, "\n\n");
for (i = 1; i <= nrules; i++)
- {
- if (!BITISSET (P, i))
- {
- fprintf (out, "#%-4d ", i);
- fprintf (out, "%s :\t", tags[rule_table[i].lhs]);
- for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
- fprintf (out, " %s", tags[*r]);
- fprintf (out, ";\n");
- }
- }
+ if (!BITISSET (P, i))
+ {
+ fprintf (out, "#%-4d ", i);
+ fprintf (out, "%s :\t", tags[rule_table[i].lhs]);
+ for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
+ fprintf (out, " %s", tags[*r]);
+ fprintf (out, ";\n");
+ }
}
if (nuseless_nonterminals > 0 || nuseless_productions > 0 || b)
fprintf (out, "\n\n");
}
\f
-#if 0 /* XXX currently unused. */
static void
dump_grammar (FILE *out)
{
int i;
rule r;
+ fprintf (out, "REDUCED GRAMMAR\n\n");
fprintf (out,
"ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nitems = %d\n\n",
ntokens, nvars, nsyms, nrules, nitems);
}
fprintf (out, "\n\n");
}
-#endif
tags[start_symbol]);
reduce_grammar_tables ();
-#if 0
- if (verbose_flag)
+
+ if (trace_flag)
{
- fprintf (out, "REDUCED GRAMMAR\n\n");
- dump_grammar ();
+ dump_grammar (stderr);
+
+ fprintf (stderr, "reduced %s defines %d terminals, %d nonterminals\
+, and %d productions.\n",
+ infile, ntokens, nvars, nrules);
}
-#endif
-
- if (statistics_flag)
- fprintf (stderr, _("reduced %s defines %d terminal%s, %d nonterminal%s\
-, and %d production%s.\n"),
- infile,
- ntokens,
- (ntokens == 1 ? "" : "s"),
- nvars,
- (nvars == 1 ? "" : "s"),
- nrules,
- (nrules == 1 ? "" : "s"));
}