Fringer EF-FX Pro version has a built-in electronic aperture ring. The usage is similar to Fujifilm XF lenses. You will be able to use Canon lenses on Fujifilm mirrorless just like native XF lenses!
It's an electronic aperture ring with contactless internal design so you don't need to worry about the contact wearing issues. When you turn that aperture ring, in case of a 85/1.4 lens it will set aperture to F1.4, F1.6, F1.8, F2.0..., F22 and 'Auto'. Every click equals to 1/3 stop. When it's set to 'Auto', aperture will be decided by the camera. Watch the following video for more details.
I heard some other smart adapter manufacturers use a button on the adapter to control the aperture. I don't think that is an effective method. Thinking about changing the aperture value from F1.4 to F16. You need to press that button dozens of times!
Fringer EF-FX Pro smart adapter let EF lenses work on Fujifilm X mount bodies. It supports AF (PDAF on X-Trans II/III and CDAF on all of them, watch this demo), electronic aperture control, EXIF recording and IS. It's expected to be released on early 2018.