[infer][ondemand] cache the results of the on-demand analysis

Summary: For the Buck integration for Java, caching when a summary is not found avoids going through the whole classpath every time a summary for the same method is not found.

Reviewed By: mbouaziz, jvillard

Differential Revision: D6402833

fbshipit-source-id: 4feb422

infer/src/backend/ondemand.ml

@@ -183,7 +183,11 @@ let analyze_proc_desc curr_pdesc callee_pdesc : Specs.summary option =
 
 (** analyze_proc_name curr_pdesc proc_name performs an on-demand analysis of proc_name triggered
     during the analysis of curr_pname *)
-let analyze_proc_name curr_pdesc callee_pname : Specs.summary option =
+let analyze_proc_name : Procdesc.t -> Typ.Procname.t -> Specs.summary option =
+  let cached_results = Typ.Procname.Hash.create 100 in
+  fun curr_pdesc callee_pname ->
+    try Typ.Procname.Hash.find cached_results callee_pname with Not_found ->
+      let summary_option =
         match !callbacks_ref with
         | None ->
             L.(die InternalError)
@@ -198,6 +202,10 @@ let analyze_proc_name curr_pdesc callee_pname : Specs.summary option =
               | None ->
                   Specs.get_summary callee_pname
             else Specs.get_summary callee_pname
+      in
+      if not (is_active callee_pname) then
+        Typ.Procname.Hash.add cached_results callee_pname summary_option ;
+      summary_option
 
 
 (** Find a proc desc for the procedure, perhaps loading it from disk. *)