[inferbo] Cache results of `replace_make_shared` call

Summary:
`replace_make_shared` is finding a constructor by iterating all fields of type structs, which may be
expensive if there are lots of fields or `replace_make_shared` is called many times with the same parameters.

Reviewed By: ngorogiannis

Differential Revision: D19446260

fbshipit-source-id: c5c279ca5

infer/src/backend/InferAnalyze.ml

@@ -14,7 +14,10 @@ module L = Logging
 module CLOpt = CommandLineOption
 
 let clear_caches () =
-  Ondemand.LocalCache.clear () ; Summary.OnDisk.clear_cache () ; Procname.SQLite.clear_cache ()
+  Ondemand.LocalCache.clear () ;
+  Summary.OnDisk.clear_cache () ;
+  Procname.SQLite.clear_cache () ;
+  BufferOverrunUtils.clear_cache ()
 
 
 let analyze_target : SchedulerTypes.target Tasks.doer =

infer/src/bufferoverrun/bufferOverrunUtils.ml

@@ -357,7 +357,17 @@ module ReplaceCallee = struct
         false
 
 
-  let get_cpp_constructor_of_make_shared tenv get_formals =
+  module CacheForMakeShared = struct
+    let results : Procname.t option Procname.Hash.t lazy_t = lazy (Procname.Hash.create 128)
+
+    let add pname value = Procname.Hash.replace (Lazy.force results) pname value
+
+    let find_opt pname = Procname.Hash.find_opt (Lazy.force results) pname
+
+    let clear () = if Lazy.is_val results then Procname.Hash.clear (Lazy.force results)
+  end
+
+  let get_cpp_constructor_of_make_shared =
     let rec strip_ttype = function
       | [] ->
           Some []
@@ -366,9 +376,12 @@ module ReplaceCallee = struct
       | _ ->
           None
     in
-    function
-    | Procname.C ({template_args= Typ.Template {args}} as name) when Procname.C.is_make_shared name
-      -> (
+    fun tenv get_formals pname ->
+      IOption.value_default_f (CacheForMakeShared.find_opt pname) ~f:(fun () ->
+          let result =
+            match pname with
+            | Procname.C ({template_args= Typ.Template {args}} as name)
+              when Procname.C.is_make_shared name -> (
               match strip_ttype args with
               | Some (class_typ_templ :: param_typs_templ) ->
                   let open Option.Let_syntax in
@@ -380,6 +393,9 @@ module ReplaceCallee = struct
                   None )
             | _ ->
                 None
+          in
+          CacheForMakeShared.add pname result ;
+          result )
 
 
   let replace_make_shared tenv get_formals pname params =
@@ -393,3 +409,5 @@ module ReplaceCallee = struct
     | None ->
         {pname; params; is_params_ref= false}
 end
+
+let clear_cache () = ReplaceCallee.CacheForMakeShared.clear ()

infer/src/bufferoverrun/bufferOverrunUtils.mli

@@ -111,3 +111,5 @@ module ReplaceCallee : sig
 
   val replace_make_shared : Tenv.t -> get_formals -> Procname.t -> (Exp.t * Typ.t) list -> replaced
 end
+
+val clear_cache : unit -> unit