Just the usual precautions, I would have thought. Lean just a few degrees, put fenders and fender board against the wall. Hold the boat into the wall with mooring warps. Depending on the height of the wall, it might be helpful to put a line around the mast. Then run long lines fore-and-aft; that is a good use for halyards to make sure you don't tilt bow-down or stern-down.