GCC C compile error, void value not ignored as it ought to be

Question

I\'m having trouble compiling some C code. When I compile, I\'l get this error:

player.c: In function ‘login’:  
player.c:54:17: error: void value not igno         


        

Answer 1

I'm going to guess that sp_session_login is declared as returning void and not sp_error and there is some alternative way of determining whether it succeeded.

Answer 2

It doesn't look like sp_session_login actually returns anything. In particular, it doesn't return an sp_error, so there's no way this could work. You can't really bypass it.

Answer 3

You must declare void functions before use them. Try to put them before the main function or before their calls. There's one more action you can do: You can tell the compiler that you will use void functions.

For exemplo, there are two ways to make the same thing:

#include <stdio.h>

void showMsg(msg){
    printf("%s", msg);
}

int main(){
    showMsg("Learn c is easy!!!");
    return 0;
}

...and the other way:

#include <stdio.h>

void showMsg(msg); //Here, you told the compiller that you will use the void function showMsg.

int main(){
    showMsg("Learn c is easy!!!");
    return 0;
}

void showMsg(msg){
    printf("%s", msg);
}

Answer 4

Where is the error line exactly?

Without further information, I'm guessing it's here:

sp_error err = sp_session_login(g_sess, username, password, remember_me);

I guess sp_session_login is returning the void.

Try:

static bool login(const char *username, const char *password) {
    sp_session_login(g_sess, username, password, remember_me);
    printf("Signing in...\n");
    return 1;
}

Answer 5

It usually means you assign the return of a void function to something, which is of course an error.

In your case, I guess the sp_session_login function is a void one, hence the error.