Question

I want to call a function low_level_init which has signature

void low_level_init(struct netif *netif)

I have tried

struct netif dummy;
low_level_init(&dummy);

but I get the error

storage size of ‘dummy’ isn’t known

I have also tried (as suggested here)

extern struct netif dummy;
low_level_init(&dummy);

but then I get the error

error: ‘dummy’ undeclared (first use in this function)

How can I call low_level_init?

Answer 1

Include the header file where that structure is defined.
Otherwise the compiler cannot know how much space to reserve.