C Linked List infinite loop - c

Question

I am trying to edit part of a backnet stack to not use malloc as it always fails. The code uses malloc to create an object and insert into a linked list. In the following code snippet I have commented out the malloc. My plan is to create a local instance of the struct and insert that into my list. I am able to insert 2 items into my list, when trying to add the third, the list is not properly terminated and I enter an infinite while loop. Can anyone see why my list is not properly terminated?
CHobjects is a stuct and I want a linked list of them. I can not use malloc to create new CHobject instances. To get around this I am attempting to create a local instance of CHobject and add that to my list.
CHobjects* newNode(instance, channel, name, description)
{
CHobjects *node;
CHobjects newNode;
node=CHobjects;
while(node!=NULL)
{
if(node->instance==instance)
return
node=node->next;
}
if(strlen((char *)objectName)>objectNameMax || strlen((char *)description)>descriptionMax)
goto cc8; //fail name or description is too long
// if((node=(CHobject *)malloc(sizeof(CHobject)))==NULL) //get a block of space for this object's info
// goto cc8; //fail if we can't get space for it
test.next=CHobjects; //link on to list
CHobjects=&test;
CHcount++;
}
This code simply adds the elements to the list, the whole code would afterwards set some variables to default values.

Answer 1

After our extensive discussion in the comments, I think it's obvious that you problem is the use of local struct instances in a global list. The structs you create on the stack become invalid on exiting the newNode() function, and the same stack space is recycled on the next call. So you link the same instance to itself, and after two calls, you've got a circular list, and enter an infinite loop.
Since you're obviously on plain C without a heap, your only chance is to roll your own struct allocator in global memory, preallocated at compile time. Declare a global array of CHobjects large enough to satisfy all of you allocations (i.e. the maximum length of the list). In your case, this seems to be 4. Here's a raw outline:
#define CHOBJECTS_MAX 4
static CHobjects gaCHobjects [CHOBJECTS_MAX];
static int giNextSlot = 0;
public: static CHobjects* Allocator ()
{
return gaCHObjects + giNextSlot++;
}
The function Allocator() returns a struct pointer from your global array and increments the giNextSlot index, so you get a new instance on each invocation. Use this pointer inside newNode() instead of a local CHobjects instance.

Answer 2

Your question is a little unclear, but I think that it's possible to give you a useful answer anyway.
The only way I can think that you can implement this is using an array as the storage for the linked list, and as a plus you will have both an array and a linked list at the same time
#include <stdio.h>
struct list {
int value;
struct list *next;
};
static void
print_list(const struct list *item)
{
while (item->next != NULL) {
fprintf(stdout, "%d\n", item->value);
item = item->next;
}
}
int
main(void)
{
struct list items[15];
size_t count;
count = sizeof items / sizeof *items - 1;
for (int index = 0; index < count; ++index) {
items[index].next = &items[index + 1];
items[index].value = index + 1;
}
items[count].next = NULL;
print_list(items);
}
As you see, you need access to the given array element to use as storage location, and the array must be valid through the life time of the linked list.