int PG::Main (int na, char** arg)
{
if (Start (na, arg))
{
PGParser::initialize (optn[MAX_SYM]);
if (PGParser::parse (input_start) > 0)
{
PrintGrammar();
PrintHtml();
if (CheckGrammar())
{
OutputLexicalSymbols();
if (BuildLR1())
{
if (ComputeLA())
{
if (OptimizeStates())
{
PrintStates();
CreateTables();
PG::Terminate (0);
return 1;
}
}
}
}
}
}
return 0;
}
int LGCheckGrammar::CheckGrammar ()
{
if (optn[LG_VERBOSE] > 2) printf ("Checking grammar for problems ...\n");
C_LENG ();
C_NULLS ();
C_HEADSYM ();
CHECK_LEXICALS ();
if (n_errors) return 0;
if (optn[LG_VERBOSE] > 2)
printf ("Checking for unreachable symbols ...\n");
P_UNREACHABLES ();
if (n_errors) return 0;
if (optn[LG_VERBOSE] > 2)
printf ("Checking for undefined symbols ...\n");
P_UNDEFINED ();
if (n_errors) return 0;
if (optn[LG_VERBOSE] > 2)
printf ("Checking for useless productions ...\n");
P_USELESS_PROD ();
if (n_errors) return 0;
if (optn[LG_VERBOSE] > 2)
printf ("Checking for null tokens ...\n");
P_NULL_TOKENS ();
if (n_errors) return 0;
if (optn[LG_VERBOSE] > 2)
printf ("Checking for unreducible symbols ...\n");
P_UNREDUCIBLES ();
if (n_errors) return 0;
if (optn[LG_VERBOSE] > 2)
printf ("Checking for cycles in grammar ...\n");
C_CYCLES();
if (n_errors) return 0;
FREE (head_sym, n_heads); // Free this, DO_BACK_SUB changes n_heads.
prt_log ("Grammar %7d rules, ", n_prods);
prt_log ("%d terminals, ", max_char_set);
prt_log ("%d nonterminals.\n", n_heads);
PrintGrammar ();
if (n_errors > 0) return (0);
FREE (head_type, n_heads);
FREE (head_line, n_heads);
FREE (prod_type, n_prods);
FREE (prod_line, n_prods);
FREE (term_line, n_terms);
if (optn[LG_VERBOSE] > 2)
printf ("Doing back-substitutions for null symbols ...\n");
DO_BACK_SUB ();
if (optn[LG_VERBOSE] > 2)
printf ("Done with back-substitutions !!!\n");
if (optn[LG_VERBOSE] > 2) PrintGrammar (); // Printing grammar for 2nd time?
return (1);
}
