Stop building higher order call graph when reaching a max number of i…

…terations

Summary:
This would help the higher order call graph building algorithm to terminate,
when there are too many parameterized targets that we need to build higher
order call graphs for.

Currently, we raise an exception when reaching a max number of iterations.

Reviewed By: arthaud

Differential Revision: D66312154

fbshipit-source-id: a2dd3701848bec485e61f4b629b86f1d2c5002bc

source/interprocedural/callGraphFixpoint.ml

@@ -162,6 +162,7 @@ let compute
       }
     ~callables_to_analyze
     ~max_iterations
+    ~error_on_max_iterations:false
     ~epoch:Fixpoint.Epoch.initial
     ~shared_models
 

source/interprocedural/fixpointAnalysis.ml

@@ -68,6 +68,8 @@ module type LOGGER = sig
     callables_to_analyze:Target.t list ->
     exn
 
+  val reached_maximum_iteration_exit : iteration:int -> callables_to_analyze:Target.t list -> unit
+
   (** This is called at the beginning of each iteration. *)
   val iteration_start
     :  iteration:int ->
@@ -753,6 +755,7 @@ module Make (Analysis : ANALYSIS) = struct
       ~context
       ~callables_to_analyze:initial_callables_to_analyze
       ~max_iterations
+      ~error_on_max_iterations
       ~epoch
       ~shared_models:shared_models_handle
     =
@@ -761,7 +764,11 @@ module Make (Analysis : ANALYSIS) = struct
       if number_of_callables = 0 then (* Fixpoint. *)
         iteration
       else if iteration >= max_iterations then
-        raise (Logger.reached_maximum_iteration_exception ~iteration ~callables_to_analyze)
+        if error_on_max_iterations then
+          raise (Logger.reached_maximum_iteration_exception ~iteration ~callables_to_analyze)
+        else
+          let () = Logger.reached_maximum_iteration_exit ~iteration ~callables_to_analyze in
+          iteration
       else
         let () = Logger.iteration_start ~iteration ~callables_to_analyze ~number_of_callables in
         let timer = Timer.start () in
@@ -856,6 +863,10 @@ module WithoutLogging = struct
     Format.asprintf "Failed to reach a fixpoint after %d iterations" iteration |> failwith
 
 
+  let reached_maximum_iteration_exit ~iteration ~callables_to_analyze:_ =
+    Log.info "Failed to reach a fixpoint after %d iterations. Terminate now." iteration
+
+
   let iteration_start ~iteration:_ ~callables_to_analyze:_ ~number_of_callables:_ = ()
 
   let iteration_end ~iteration:_ ~expensive_callables:_ ~number_of_callables:_ ~timer:_ = ()
@@ -884,21 +895,32 @@ struct
       ()
 
 
-  let reached_maximum_iteration_exception ~iteration ~callables_to_analyze =
-    let max_to_show = 15 in
-    let bucket =
-      callables_to_analyze |> List.map ~f:Target.show_pretty |> List.sort ~compare:String.compare
-    in
+  let show_callables ~max_to_show callables =
+    let bucket = callables |> List.map ~f:Target.show_pretty |> List.sort ~compare:String.compare in
     let bucket_len = List.length bucket in
     Format.sprintf
-      "Failed to reach a fixpoint after %d iterations (%d callables: %s%s)"
-      iteration
-      (List.length callables_to_analyze)
+      "%s%s"
       (String.concat ~sep:", " (List.take bucket max_to_show))
       (if bucket_len > max_to_show then "..." else "")
+
+
+  let reached_maximum_iteration_exception ~iteration ~callables_to_analyze =
+    Format.sprintf
+      "Failed to reach a fixpoint after %d iterations (%d callables: %s)"
+      iteration
+      (List.length callables_to_analyze)
+      (show_callables ~max_to_show:15 callables_to_analyze)
     |> failwith
 
 
+  let reached_maximum_iteration_exit ~iteration ~callables_to_analyze =
+    Log.info
+      "Failed to reach a fixpoint after %d iterations. Terminate now  (%d callables: %s)"
+      iteration
+      (List.length callables_to_analyze)
+      (show_callables ~max_to_show:15 callables_to_analyze)
+
+
   let iteration_start ~iteration ~callables_to_analyze ~number_of_callables =
     let witnesses =
       if number_of_callables <= 6 then

source/interprocedural/fixpointAnalysis.mli

@@ -52,6 +52,8 @@ module type LOGGER = sig
     callables_to_analyze:Target.t list ->
     exn
 
+  val reached_maximum_iteration_exit : iteration:int -> callables_to_analyze:Target.t list -> unit
+
   (** This is called at the beginning of each iteration. *)
   val iteration_start
     :  iteration:int ->
@@ -204,6 +206,7 @@ module Make (Analysis : ANALYSIS) : sig
     context:Analysis.context ->
     callables_to_analyze:Target.t list ->
     max_iterations:int ->
+    error_on_max_iterations:bool ->
     epoch:Epoch.t ->
     shared_models:shared_models ->
     t

source/interprocedural/test/callGraphFixpointTest.ml

@@ -22,7 +22,7 @@ module Expected = struct
   }
 end
 
-let assert_higher_order_call_graph_fixpoint ~source ~expected () context =
+let assert_higher_order_call_graph_fixpoint ?(max_iterations = 10) ~source ~expected () context =
   let handle = "test.py" in
   let configuration, pyre_api =
     initialize_pyre_and_fail_on_errors ~context ~handle ~source_content:source ~models_source:None
@@ -63,7 +63,7 @@ let assert_higher_order_call_graph_fixpoint ~source ~expected () context =
       ~dependency_graph
       ~override_graph_shared_memory
       ~initial_callables
-      ~max_iterations:10
+      ~max_iterations
   in
   List.iter expected ~f:(fun { Expected.callable; call_graph; returned_callables } ->
       let actual_call_graph =
@@ -158,6 +158,61 @@ let test_higher_order_call_graph_fixpoint =
              ]
            ();
       labeled_test_case __FUNCTION__ __LINE__
+      @@ assert_higher_order_call_graph_fixpoint
+           ~source:
+             {|
+     def foo():
+       return 0
+     def bar(arg):
+       return foo
+     def baz():
+       return bar(foo)
+  |}
+           ~max_iterations:1
+           ~expected:
+             [
+               {
+                 Expected.callable =
+                   Target.Regular.Function { name = "test.baz"; kind = Normal }
+                   |> Target.from_regular;
+                 call_graph =
+                   [
+                     ( "7:9-7:17",
+                       LocationCallees.Singleton
+                         (ExpressionCallees.from_call
+                            (CallCallees.create
+                               ~call_targets:
+                                 [
+                                   CallTarget.create
+                                     (create_parameterized_target
+                                        ~regular:
+                                          (Target.Regular.Function
+                                             { name = "test.bar"; kind = Normal })
+                                        ~parameters:
+                                          [
+                                            ( create_positional_parameter 0 "arg",
+                                              Target.Regular.Function
+                                                { name = "test.foo"; kind = Normal }
+                                              |> Target.from_regular );
+                                          ]);
+                                 ]
+                               ())) );
+                     ( "7:13-7:16",
+                       LocationCallees.Singleton
+                         (ExpressionCallees.from_attribute_access
+                            (AttributeAccessCallees.create
+                               ~callable_targets:
+                                 [
+                                   CallTarget.create_regular
+                                     (Target.Regular.Function { name = "test.foo"; kind = Normal });
+                                 ]
+                               ())) );
+                   ];
+                 returned_callables = [];
+               };
+             ]
+           ();
+      labeled_test_case __FUNCTION__ __LINE__
       @@ assert_higher_order_call_graph_fixpoint
            ~source:{|
      def foo():

source/interprocedural_analyses/taint/taintAnalysis.ml

@@ -828,6 +828,7 @@ let run_taint_analysis
         }
       ~callables_to_analyze
       ~max_iterations:100
+      ~error_on_max_iterations:true
       ~epoch:Taint.TaintFixpoint.Epoch.initial
       ~shared_models
   in

source/interprocedural_analyses/taint/test/fixpointTest.ml

@@ -75,6 +75,7 @@ let assert_fixpoint
         }
       ~callables_to_analyze
       ~max_iterations:100
+      ~error_on_max_iterations:true
       ~epoch:TaintFixpoint.Epoch.initial
       ~shared_models
   in

source/interprocedural_analyses/taint/test/missingFlowsTest.ml

@@ -86,6 +86,7 @@ let assert_fixpoint
         }
       ~callables_to_analyze
       ~max_iterations:100
+      ~error_on_max_iterations:true
       ~epoch:TaintFixpoint.Epoch.initial
       ~shared_models
   in

source/interprocedural_analyses/taint/test/testHelper.ml

@@ -838,6 +838,7 @@ let end_to_end_integration_test path context =
           }
         ~callables_to_analyze
         ~max_iterations:100
+        ~error_on_max_iterations:true
         ~epoch:TaintFixpoint.Epoch.initial
         ~shared_models
     in