This information is based on my personal experience. Cracker Barrel is helpfully the same no matter which location you eat at. Factors like that help us GF folks out tremendously! I have eaten at many CBs.
Eggs, bacon, fried apples, and grits are traditionally all safe. They are cooked on their own equipment. Eggs and bacon are done on a separate grill from the pancakes, biscuits, etcetera. Waitresses have provided me with the ingredients and prep methods of the apples and grits. I have never gotten sick from any of these foods at any CB, and I’ve eaten at a number of them up and down the east coast, and in Arizona.
You do, however, need to tell your server that you are gluten intolerant, have Celiac’s Disease, etcetera, and that it is VERY important that nothing with flour in it of any kind comes in contact with your plate.
You may have to tell them it’s an allergy to make some of them understand. I had one waitress once who was also a nurse and she was fabulous, but most people didn’t know what I was talking about unless I called it an allergy instead of an autoimmune disease.
And, as always, ask. You never know when a restaurant will change suppliers.