[Infer][Perf] Make reports more human readable

Reviewed By: ezgicicek

Differential Revision: D12956943

fbshipit-source-id: d94dcaed4

infer/src/backend/Differential.ml

@@ -144,9 +144,15 @@ let issue_of_cost cost_info ~delta ~prev_cost ~curr_cost =
       | `Increased ->
           Format.fprintf fmt "increased"
     in
-    Format.asprintf "Max degree %a from %a to %a. Cost is %a (degree is %a)" pp_delta delta
-      CostDomain.BasicCost.pp_degree prev_cost CostDomain.BasicCost.pp_degree curr_cost
-      CostDomain.BasicCost.pp curr_cost CostDomain.BasicCost.pp_degree curr_cost
+    let pp_raw_cost fmt cost_polynomial =
+      if Config.developer_mode then
+        Format.fprintf fmt " Cost is %a (degree is %a)" CostDomain.BasicCost.pp cost_polynomial
+          CostDomain.BasicCost.pp_degree cost_polynomial
+      else ()
+    in
+    Format.asprintf "Complexity %a from %a to %a.%a" pp_delta delta
+      CostDomain.BasicCost.pp_degree_hum prev_cost CostDomain.BasicCost.pp_degree_hum curr_cost
+      pp_raw_cost curr_cost
   in
   let line = cost_info.Jsonbug_t.loc.lnum in
   let column = cost_info.Jsonbug_t.loc.cnum in

infer/src/bufferoverrun/itv.ml

@@ -412,6 +412,26 @@ module NonNegativePolynomial = struct
         Format.pp_print_int fmt (NonNegativeNonTopPolynomial.degree p)
 
 
+  let pp_degree_hum fmt p =
+    match p with
+    | Top ->
+        Format.pp_print_string fmt "Top"
+    | NonTop p -> (
+      match NonNegativeNonTopPolynomial.degree p with
+      | 0 ->
+          Format.pp_print_string fmt "constant"
+      | 1 ->
+          Format.pp_print_string fmt "linear"
+      | 2 ->
+          Format.pp_print_string fmt "quadratic"
+      | 3 ->
+          Format.pp_print_string fmt "cubic"
+      | 4 ->
+          Format.pp_print_string fmt "quartic"
+      | d ->
+          Format.fprintf fmt "O(N^%d)" d )
+
+
   let encode astate = Marshal.to_string astate [] |> B64.encode
 
   let decode enc_str = Marshal.from_string (B64.decode enc_str) 0

infer/src/bufferoverrun/itv.mli

@@ -58,6 +58,8 @@ module NonNegativePolynomial : sig
 
   val pp_degree : Format.formatter -> astate -> unit
 
+  val pp_degree_hum : Format.formatter -> astate -> unit
+
   val encode : astate -> string
 
   val decode : string -> astate