It depends entirely what your goals are. If you want to stay controlled and without diabetes complications, then there are plenty of foods to avoid. Starches, grains, sweeteners, certain sugar alcohols, low fat foods(usually contain more sugars), milk, yoghurt, sweets, cakes, biscuits, fruit(lots of fructose), root veg such as potatoes(too much starch), beers ciders, perries. I also limit my carbohydrate consumption. On that way of eating you eat no processed foods, so the need to limit salt disappears.
It works, my HbA1c is now 42.
\of course you can eat what you like, and just inject insulin, but I prefer to reduce my insulin needs as much as possible. This limits weight gain.