Compile this program with gcj -g:

public class jmain
{
  public static void main (String[] args)
    {
        return;
    }
}

There are five constructs with line numbers in the readelf -wi output (search for decl_line).  The class jmain, the method main, and the synthetic constructor all have line number zero; they should be 1, 3, and not-sure-but-probably-1 respectively.  The argument args is listed on line 5 instead of line 3 where it is declared in the source.  The synthetic "this" argument to the synthetic constructor has line 1.