dereferencing pointer to incomplete type

[killermelga]

im getting the error on the threads name whenever a try to access an attribute of a struct

here is the relevant code

the structure

typedef struct logrw_struct_ {
    
    unsigned int num_reg, num_bks, bks_sz;
    unsigned int pos_livre;
    
    blocks_t* bks_a, *bks_i;
    blocks_t* regs[0];
}logrw_struct_t;

initializing the structure

logrw_struct_t* logrw_init(unsigned int num_reg, unsigned int array_dim, unsigned int bloco_dim) {
    
    int i;
    
    logrw_struct_t *log = (logrw_struct_t*) 
        malloc(sizeof(logrw_struct_t) + num_reg);
    
    log->num_reg = num_reg;
    log->num_bks = array_dim;
    log->bks_sz = bloco_dim;
    
    log->bks_a = block_new(array_dim, bloco_dim);
    log->bks_i = block_new(array_dim, bloco_dim);

    for(i = 0; i<num_reg; i++){
        log->regs[i] = log->bks_a;
    }
    log->pos_livre = i;
    
    return log;
}

the main where i get the error

int main(){
    
    logrw_struct_t *log;
    log = logrw_init(2, 12, 4);
    printf("registos->%d\nnum_blocos->%d\n", log->num_registos, log->num_blocos);
                 
    return 0;
}

[Salem]

The point of incomplete types is to create opaque interfaces which hide implementation detail.

Your logrw API needs to provide some get methods, so you can write

printf("registos->%d\nnum_blocos->%d\n", logrw_getRegs(log), logrw_getBlocks(log) );

[killermelga]

but there is no way of acessing directly to the log values, with the ->?

[killermelga]

but there is no way of acessing directly to the log values, with the ->?
because i have another API thats supposed to receive blocks_t* and returns the number of blocks, but if i make

printf("registos->%d\nnum_blocos->%d\n", logrw_getRegs(log), logrw_getBlocks(log->bks_a) );

it gives the same error

[Salem]

> but there is no way of acessing directly to the log values, with the ->?
Yes, you could include the header file containing the struct declaration, but that would defeat the whole point.

> printf("registos->%d\nnum_blocos->%d\n", logrw_getRegs(log), logrw_getBlocks(log->bks_a) );
> it gives the same error
Of course it would, you still have log->someMember in there.
You can ONLY use log here in main, not log->someMember.