Code

 Header...
#define NX 2
#define NY 2
#define IMAX 16

typedef struct foostr {
  int n;
  float vals[];
}Foostr;

void foobar (float *,int);

 void foo(int x){
   ... 

»  printf("foo! am here\n");
}

 void tfun(int x){
   ... 

»  printf("tfun! am here %d\n", x);
}

 int main(){
   ... 

»  int found=0;
»  char image[NY][NX];
»  int ix, iy, nf;
»  char letters[32]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
»  int sizes[IMAX];

»  Foostr *q;

»  q=malloc(sizeof *q+4*sizeof q->vals[0]);
»  q->vals2=5.6;

»  tfun((foo(1),1));

»  return 0;
}