c linked list test

main.c

#include <stdio.h>
#include <stdlib.h>

struct Node {
    int value;
    struct Node* prev, * next;
    struct Node* first, * last;
};

void list_push(struct Node* list, struct Node* location, int value) {
    struct Node* node = malloc(sizeof(struct Node*));
    node->value = value;
    node->prev  = location ? location->prev : list->last;
    node->next  = location;
    if (node->prev)              node->prev->next = node;
    if (location)                location->prev   = node;
    if (location == list->first) list->first      = node;
    if (!location)               list->last       = node;
}

void list_free(struct Node* list) {
    while (list->first) {
        struct Node* location = list->first;
        struct Node* prev = location->prev;
        struct Node* next = location->next;
        if (prev)                    prev->next  = next;
        if (next)                    next->prev  = prev;
        if (location == list->first) list->first = next;
        if (location == list->last)  list->last  = prev;
        free(location);
    }
}

int main(int argc, char** argv) {
    struct Node list = {
        .first = NULL, 
        .last  = NULL, 
    };
    list_push(&list, list.first, 1);
    list_push(&list, list.first, 3);
    list_push(&list, NULL, 15);
    list_push(&list, list.first, 4);
    for (struct Node* i = list.first; i != NULL; i = i->next) {
        printf("%i\n", i->value);
    }
    list_free(&list);
    return 0;
}