dereferencing pointer to incomplete type|

Question

this is my header file

   #include<stdio.h>
   #include<stddef.h>

char memory[25000]; //Declare an  array of 25000 bytes in size

//Define data structure to save the details of the each memory block
struct metaData{
int status; //save the status of the block  is free or whether it is already        allocated
size_t bSize; //save the block size in bytes
struct metaData *next; //save the pointer to next header
 };

struct header *firstBlock=(void*)memory; //Initialise a pointer to the    starting address of the memory


void initializeMemory(){
firstBlock->bSize=25000-sizeof(struct metaData);
firstBlock->status=1;
firstBlock->next=NULL;
}

and when I try to use this InitializeMemory() it says dereferencing pointer to incomplete type and pointed to InitializeMemory() funtion. What is the error of this?

Answer 1

You've declared firstBlock as a struct header * . You're receiving the "incomplete type" error because you haven't actually defined a structure called struct header - you've defined struct metaData instead.

Use struct metaData *firstBlock instead and it should work.