incompatible implicit declaration

[ali hagigat]

No Bill, i do not include stdio.h on purpose!

My program is exactly as follows:
main(){
	printf("kkkkkkkk=\n");
}
and I compile it as:
gcc -o prog1 prog1.c
prog1.c: In function ‘main’:
prog1.c:2: warning: incompatible implicit declaration of built-in
function ‘printf’

I could not get my answer by google. I guess that printf is a built-in
function and has a function prototype and probably the built-in
version is being used here. So why implicit declaration? and how it is
 incompatible?
Is there a complete list of GCC error and warning messages (and their causes)?
Regards

On Sun, Dec 26, 2010 at 5:33 PM, Bill McEnaney <bill@rkirkpat.net> wrote:
> Did you include stdio.h?
>