YACC : Position is not getting updated

Question

I'm doing some simple lex and yacc exercises, and I've noticed the positions in @1 @2 @3 etc are not getting updated... I thought that was automatic ? Did I misunderstand something ? Do I have to manually update yylloc in my lex rules ?

Using the following code and input file, this is the output : output

$ main < input.txt
Warning line 1 : invalid date
Warning line 1 : invalid time
Warning line 1 : invalid date
Warning line 1 : invalid time
[...]

The errors are expected, but they shouldn't all be on line 1.

---

y.tab.y

%{
    #include <stdio.h>
    int yyerror(char* msg);
    int yylex(void);

    int table[100][10];
    int isValidTime(char *time);
    int isValidDate(char *date);
%}
%union {
    char * string;
    int integer;
}
%token IDF EOL DATE TIME INT
%type<string> DATE TIME
%type<integer> INT
%%
file
    : first_line EOL content
    ;
first_line
    : first_line IDF
    |
    ;
content
    : content one_line EOL
    |
    ;
one_line
    : DATE TIME values {
        if (!isValidDate($1)) {
            fprintf(
                stderr,
                "Warning line %d : invalid date\n",
                @1.last_line
            );
        }
        if (!isValidTime($2)) {
            fprintf(
                stderr, 
                "Warning line %d : invalid time\n", 
                @2.first_line
            );
        }
    }
    ;
values
    : values INT
    |
    ;
%%

int isValidTime(char *time) {
    return 0;
}
int isValidDate(char *date) {
    return 0;
}

---

lex.yy.l

%{
    #include "y.tab.h"
%}
c [0-9]
%%
[a-zA-Z][a-zA-Z0-9]* {return IDF;}
{c}{c}:{c}{c}:{c}{c} {
    yylval.string = yytext;
    return TIME;
}
{c}{c}\/{c}{c}\/{c}{c} {
    yylval.string = yytext;
    return DATE;
}
{c}* {
    yylval.integer = atoi(yytext); 
    return INT;
}
\n {return EOL;}
. {;}
%%

---

main.c

#include <stdio.h>
#include <stdlib.h>

#include "y.tab.h"

int main(void) { return yyparse(); }

---

input.txt

one two three four
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4
01/01/01 00:00:00 1 2 3 4