Hi Atalanta, For it to flower well, it needs to be in a good position, sun or part-shade (not too shady) and with the correct pruning, it should flower, obviously, it has to flower before you will see the berries.
If I knew how to send a link, I would direct you to the RHS site or similar equivalent, but maybe you can look there for advice.
C. salisifolious can become a large sprawling shrub (depending on variety) but can easily be contained with formative pruning. Good Luck.