error C2016 (C requires that a struct or union has at least one member) and structs typedefs

Question

In my C-project there are some entities. For every entity there are header file and a source file. In the header file I define couple of structs.

For example, let's say our entity is Baz. Then we have baz.h and baz.c. Inside baz.h there will be something like:

typedef struct baz_t {
    int i; 
    char c;
} Baz;

typedef struct bazbaz_t {
    Baz *b;
} BazBaz;

In the same way, I may define an entity Foo which it's struct contain a pointer to another struct. Something like:

typedef struct foo_t {
    Baz *b; 
} Foo;

So in conclusion, every entity can have several structs and a struct can have a pointer to another struct in the same entity or a pointer to a struct from another entity.

Finally, those structs (obviously) should be used by other files in the project.

I've created a main.h\ main.c which #includes all the entities and each entity have an include to main.h. I've also added include-guards in order to avoid circular dependency.

Problem is:
I get all those C2016 errors; I've tried to move the typedefs to main.h but problem haven't been solved.

How do I solve this problem? I am more then certain there's a right paradigm to handle this kind of situation, but I'm relatively new with C.

Answer 1

You are using a your newly created typename Baz as a name here:

 Baz *Baz; 

it is sort of the same as doing:

int int;

which is also illegal, because ìnt` is a typename. If you change it to:

Baz *baz; 

it should work.