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Re: "warning: assignment from incompatible pointer type [enabled by default]"

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On Fri, 4 Jan 2013 18:14:46 -0600 (CST), galois271@gmail.com wrote:

>Any help here would be GREATLY appreciated!  Thanks!!!
>
>Here is my compiler response:
>
>"gcc "./Desktop/C Programs/HeadFirstTests.c" -o "./Desktop/C Programs/HFT" && "./Desktop/C Programs/HFT" 
>./Desktop/C Programs/HeadFirstTests.c: In function ‘addFirst’:
>./Desktop/C Programs/HeadFirstTests.c:40:16: warning: assignment from incompatible pointer type [enabled by default]
>./Desktop/C Programs/HeadFirstTests.c: In function ‘printList’:
>./Desktop/C Programs/HeadFirstTests.c:51:7: warning: assignment from incompatible pointer type [enabled by default]
>"
>
>
>/* This program builds 
>   a basic linked list.
>   gcc "./Desktop/C Programs/HeadFirstTests.c" -o "./Desktop/C Programs/HFT" && "./Desktop/C Programs/HFT"  
>*/
>
>#include <stdio.h>
>#include <stdlib.h>
>#include <string.h>
>
>typedef struct {           // Define a linked list node

At this point, you have "forward declared" a tagless structure type.

>     char *name;
>     struct LLNODE *next;

At this point, you have "forward declared" a structure type called
struct LLNODE.

>}LLNODE;

At this point, you have finished the definition of the tagless
structure and created a type LLNODE that is an alias for this
structure.  Note that LLNODE is a completely different type than
struct LLNODE.

>
>
>void addFirst(char *data);  //Declare function prototypes
>void printList(void);
>
>LLNODE *head = NULL;  //Defind global pointer variable head
>
> 
>int main(int argc, char *argv[])
>{
>	
>    addFirst("Johnson");
>    addFirst("Robert");
>    addFirst("Jerimiah");
>    printList();
>    
>    
>   return EXIT_SUCCESS; 
>}
>
>void addFirst(char *data)
>{
>	
>	LLNODE *newNode;
>	newNode = malloc(sizeof(LLNODE));
>	newNode->name = data;
>	newNode->next = head;  //Keep getting errors here.

next is a pointer to struct LLNODE.  head is a pointer to LLNODE.  As
noted above, the two are not the same or even compatible types.

>	head = newNode;
>	
>}

The solution to your problem is to add the tag LLNODE to you tagless
structure so that LLNODE and struct LLNODE refer to the same type.

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Thread

"warning: assignment from incompatible pointer type [enabled by default]" galois271@gmail.com - 2013-01-04 18:14 -0600
  Re: "warning: assignment from incompatible pointer type [enabled by default]" "LeJacq, Jean Pierre" <jeanpierre.lejacq@quoininc.com> - 2013-02-26 10:48 -0600
  Re: "warning: assignment from incompatible pointer type [enabled by default]" espie@lain.home (Marc Espie) - 2013-02-26 10:51 -0600
  Re: "warning: assignment from incompatible pointer type [enabled by default]" Barry Schwarz <schwarzb@dqel.com> - 2013-02-26 10:47 -0600
  Re: "warning: assignment from incompatible pointer type [enabled by default]" Jasen Betts <jasen@xnet.co.nz> - 2013-02-26 10:51 -0600
  Re: "warning: assignment from incompatible pointer type [enabled by default]" Andrei Voropaev <avorop@mail.ru> - 2013-02-26 10:51 -0600
  Re: "warning: assignment from incompatible pointer type [enabled by default]" gordonb.zh6m9@burditt.org (Gordon Burditt) - 2013-02-26 10:51 -0600

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