In TN it is only illegal to carry inside a building which holds a license to dispense liquor by the drink.
Hence, you can legally carry:
-Outside of a building inside which liquor is sold for consuption.
-Inside of a business which only sells alchohol, but does not serve it for on-site consumption.
-Inside of a building which only serves beer, but not liquor (since 'beer' is not viewed as alcohol, in TN). Take note, however, that malt liquor and wine-coolers are considered 'alcohol'.
So, yes, you can carry inside quickie-marts, gas-stations, Wal-Mart, etc... since they do not sell for on-site consumption. You can even carry inside a liquor store (as long as there is no bar).