QParser in qlalr exemple won't compile

calc_lex.cpp: In function ‘int yy_get_next_buffer()’: 
calc_lex.cpp:1100:44: warning: comparison between signed and 
unsigned integer expressions [-Wsign-compare] 
  if ((int) ((yy_n_chars) + number_to_move) > YY_CURRENT_BUFF 
                                            ^ 
calc_lex.cpp: In function ‘void calc_init_buffer(YY_BUFFER_ST
ATE, FILE*)’: 
calc_lex.cpp:1422:61: error: ‘isatty’ was not declared in thi
s scope 
 yy_is_interactive = file ? (isatty( fileno(file) ) > 0) : 0; 
                                                  ^ 
calc_lex.cpp: At global scope: 
calc_lex.cpp:1176:17: warning: ‘void yyunput(int, char*)’ def
ined but not used [-Wunused-function] 
     static void yyunput (int c, char * yy_bp ) 
                 ^ 
Makefile:707 : la recette pour la cible « .obj/calc_lex.o » a
 échouée