cmListFileLexer.c:1578:17: warning: unused function 'yyunput'
[-Wunused-function]
    static void yyunput (int c, char * yy_bp , yyscan_t yyscanner)
                ^
cmListFileLexer.c:1626:16: warning: function 'input' is not needed and
will not be emitted [-Wunneeded-internal-declaration]
    static int input  (yyscan_t yyscanner)
               ^