[Perf] Better message for PERF VARIATION type

Reviewed By: ddino

Differential Revision: D13118585

fbshipit-source-id: 219b16236

infer/src/backend/Differential.ml

@@ -145,19 +145,19 @@ let issue_of_cost cost_info ~delta ~prev_cost ~curr_cost =
         | `Increased ->
             Format.fprintf fmt "increased"
       in
-      let pp_raw_cost fmt cost_polynomial =
+      let pp_extra_msg fmt cost_polynomial =
         if Config.developer_mode then
-          Format.fprintf fmt " Cost is %a (degree is %a)" CostDomain.BasicCost.pp cost_polynomial
+          Format.fprintf fmt "Cost is %a (degree is %a)" CostDomain.BasicCost.pp cost_polynomial
             CostDomain.BasicCost.pp_degree cost_polynomial
-        else ()
+        else Format.fprintf fmt "Please make sure this is an expected change."
       in
-      Format.asprintf "Complexity of this function has %a from %a to %a.%a"
+      Format.asprintf "Complexity of this function has %a from %a to %a. %a"
         (MarkupFormatter.wrap_bold pp_delta)
         delta
         (MarkupFormatter.wrap_monospaced CostDomain.BasicCost.pp_degree_hum)
         prev_cost
         (MarkupFormatter.wrap_monospaced CostDomain.BasicCost.pp_degree_hum)
-        curr_cost pp_raw_cost curr_cost
+        curr_cost pp_extra_msg curr_cost
     in
     let line = cost_info.Jsonbug_t.loc.lnum in
     let column = cost_info.Jsonbug_t.loc.cnum in