dereferencing pointer to incomplete type

Question

i'm trying to implement tree structure in c:

this part is from the header file:

typedef struct SP_Tree_Node
{
    char * value;
    struct Node * children;
    int indexOfLastChild;
} Node;

typedef struct SP_Tree
{
    Node root;
} Tree;

when i'm trying to insert new Node into children array the next error appears: "dereferencing pointer to incomplete type" this is the code: (tree's type is Tree *)

Node * newNode = (Node*) malloc(sizeof(Node*));
tree->root.children[tree->root.indexOfLastChild] = newNode;

what am i doing wrong? thank you!!

Answer 1

struct Node is different from Node , and it doesn't seem you defined `struct Node.

Try changing struct Node * children; in the declaration of struct SP_Tree_Node to struct SP_Tree_Node * children;

UPDATE:

You use array of Node* , so the declaration should be struct SP_Tree_Node ** children; (add one more asterisk).