# include "y1.h" 

/*
 * ycpfir.1c
 *
 * Modified to make debug code conditionally compile.
 * 28-Aug-81
 * Bob Denny
 */


void cpfir( )



{
  /* compute an array with the first of nonterminals */
  register * p,
         * * s,
             i,
         * * t,
             ch,
             changes;

  zzcwp   = &wsets[ nnonter ];
  NTLOOP( i )

    {
      aryfil( wsets[ i ].ws.lset, tbitset, 0 );
      t = pres[ i + 1 ];
      for ( s = pres[ i ]; s < t; ++s )

        {
          /* initially fill the sets */
          for ( p = *s; ( ch = *p ) > 0; ++p )

            {
              if ( ch < NTBASE )

                {
                  SETBIT( wsets[ i ].ws.lset, ch );
                  break ;
                }
              else
                if ( !pempty[ ch - NTBASE ] )
                  break ;
            }
        }
    }

  /* now, reflect transitivity */

  changes = 1;
  while ( changes )

    {
      changes = 0;
      NTLOOP( i )

        {
          t = pres[ i + 1 ];
          for ( s = pres[ i ]; s < t; ++s )

            {
              for ( p = *s; ( ch = ( *p - NTBASE ) ) >= 0; ++p )

                {
                  changes |= setunion( wsets[ i ].ws.lset,
                                       wsets[ ch ].ws.lset );
                  if ( !pempty[ ch ] )
                    break ;
                }
            }
        }
    }

  NTLOOP( i )
    pfirst[ i ] = flset( &wsets[ i ].ws );
  # ifdef debug
  if ( ( foutput != NULL ) )

    {
      NTLOOP( i )

        {
          fprintf( foutput, "\n%s: ", nontrst[ i ].name );
          prlook( pfirst[ i ] );
          fprintf( foutput, " %d\n", pempty[ i ] );
        }
    }
    # endif 
}