Bison and Flex Header directive error

Question

I'm getting this problem "%Header is not a valid directive".

This is the .y :

    %header{

#include "yystype.h"
#include<stdio.h> 
#include"analex.h" 
extern int yylex(void);
extern char *yytext;
extern int linea;
extern FILE *yyin;
void yyerror(const char *);
%}

%token ESCRIBIR 
%token <valor> NUMERO 
%type <valor> expr term fact

%define PURE 
%define STYPE YY_parse_STYPE 
%%

entrada : instrucciones 
;
instrucciones : instruccion | instrucciones instruccion 
;
instruccion : escritura 
;
escritura : ESCRIBIR '(' expr ')' ';' 
{printf("La expresion vale: %i\n",$3);} 
;
expr : expr '+' term 
{$$ = $1+$3;} 
| expr '-' term 
{$$ = $1-$3;} 
| term {$$ = $1;} 
;

term : term '*' fact 
{$$=$1*$3;}
| term '/' fact 
{$$ = $1/$3;} 
| fact 
{$$=$1;} 
;
fact : '(' expr ')' 
{$$=$2;} 
| NUMERO 
{$$=$1;} 
; 
%% 
void yyerror(char *s) 
{ 
printf("ERROR: (%s)\n",yytext); 
} 

The .l

%header{ 
#include "yystype.h" 
%} 
%{ 
#include <stdlib.h> 
#include "anasint.h" 
%}
letra [A-Za-z] 
digito [0-9] 
numero {digito}+ 
blanco [ \t\n]
%define LEX_PARAM YY_parse_STYPE *yylval
%% 
{blanco}* {;} 
{numero} {yylval->valor=atoi(yytext); return(NUMERO);} 
escribir {return(ESCRIBIR);} 
. {return(yytext[0]);} 
%% 

And the yystype.h

#ifndef _YYSTYPE_H 
#define _YYSTYPE_H 
typedef union{ 
int valor;} YY_parse_STYPE; 
#endif 

Please if someone knows what's the error here, feel free to tell me. The bison version is the 2.4.1 and flex 2.5

Answer 1

I think the reason you are getting the message:

"%Header is not a valid directive".

Is because "%Header is not a valid directive".

Checking the manual for flex and bison I see no %Header directive described. It is not in the manual, it is not valid.

If you remove the text header so that you have %{ you will no longer get the message.

I am puzzled why you thought there might be one; where did that information come from....