‘YYSTYPE’ has no member named '--' for union type

Question

I have declared the YYSTYPE union as

%union
{
        char* stringValue;
        union int_double_string* ids;
}

int_double_string is declared as

union int_double_string
{
        short type;     //0:int 1:double 2:string
        int intValue;
        double doubleValue;
        char* stringValue;
};

Some tokens

%token <stringValue> KEY
%token <int_double_string> VALUE
%token <stringValue> COMMENT    
%type <stringValue> pair
%type <int_double_string> key_expr

But where-ever I use token VALUE, it gives me that common error.

‘YYSTYPE’ has no member named ‘int_double_string’

pair:
        KEY ws '=' ws VALUE     {
                char S5[15];
                addPair($1, $5);   //Error here and where-ever I use $5 in this function
                ...

Why is this so though I've declared it correctly? I've used the variable in my lex file as well. Its showing no error there.

lex file

{integer}       {
                yylval.ids = malloc(sizeof(union int_double_string));
                yylval.ids->type = 0;
                yylval.ids->intValue = atoi(yytext);
                return VALUE;
        }

I think it has something to with the concept of union inside a union.

What to do?

Answer 1

‘YYSTYPE’ has no member named ‘int_double_string’

The id in %type <id> and %token <id> needs to be a field in the yyunion.

So, the tokens defined as type int_double_string need to be type ids

%token <int_double_string> VALUE
%type <int_double_string> key_expr

like this

%token <ids> VALUE
%type <ids> key_expr

And the second argument to addPair should be a union int_double_string*

In typical yacc usage you would put all these fields:

short type;     //0:int 1:double 2:string
int intValue;
double doubleValue;
char *stringVal;

Into the yyunion itself and not have a union field in yyunion. I'm not saying you can't but it is unusual.