I remember around 20 years ago when Texas first began concealed licensing. The first thing many of the restaurants did was post signs saying something to the effect of "no handguns allowed". This did not make you, the concealed weapon holder a law breaker if you carried your gun into the restaurant! If they asked you to leave because you were armed, legally, and you did not, the authorities could charge you with trespass and trespass only.
Soon, very soon, after the lawyers had a chance to chew on this concept of not "allowing" licensed CHL folks in their clients place of business (i.e. restaurants) the signs began to come down quite rapidly.
I guess the learned barristers determined that if I brought my family into a restaurant, had to leave my "legal" weapon in my truck (gave up my right in Texas to protect myself and my family). The lawyers suggested to their restaurant clients they might want to rethink the forbading concept of "no guns" If a man left his licensed carry weapon in his truck, to eat in a restaurant that nobody had guns, and something happened in the way of a shooting, the onerous to protect the customers came to rest solely on the shoulders of the restaurant to protect the customers even more diligently than ever. This is how it was explained to me.
I will ask Chilis and Sonic if this is their policy and I too will be a former customer.