refactor objc dispatch models

Summary: Move Objective-C dispatch models to IR to be able to reuse the same approach in Pulse.

Reviewed By: skcho

Differential Revision: D28550389

fbshipit-source-id: 163826647

infer/src/IR/ObjCDispatchModels.ml

@@ -0,0 +1,29 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+open! IStd
+
+let dispatch_models =
+  [ "_dispatch_once"
+  ; "dispatch_async"
+  ; "dispatch_after"
+  ; "dispatch_group_async"
+  ; "dispatch_barrier_async"
+  ; "dispatch_group_notify" ]
+
+
+let is_model proc_name = List.mem dispatch_models ~equal:String.equal (Procname.to_string proc_name)
+
+let get_dispatch_closure_opt actual_params =
+  List.find_map actual_params ~f:(fun (exp, _) ->
+      match exp with
+      | Exp.Closure c when Procname.is_objc_block c.name ->
+          (* We assume that for these modelled functions, the block passed as parameter doesn't
+             have arguments, so we only pass the captured variables. *)
+          let args = List.map ~f:(fun (id_exp, _, typ, _) -> (id_exp, typ)) c.captured_vars in
+          Some (c.name, args)
+      | _ ->
+          None )

infer/src/IR/ObjCDispatchModels.mli

@@ -8,3 +8,5 @@
 open! IStd
 
 val is_model : Procname.t -> bool
+
+val get_dispatch_closure_opt : (Exp.t * Typ.t) list -> (Procname.t * (Exp.t * Typ.t) list) option

infer/src/biabduction/ObjCDispatchModels.ml

@@ -1,18 +0,0 @@
-(*
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *)
-open! IStd
-
-let dispatch_models =
-  [ "_dispatch_once"
-  ; "dispatch_async"
-  ; "dispatch_after"
-  ; "dispatch_group_async"
-  ; "dispatch_barrier_async"
-  ; "dispatch_group_notify" ]
-
-
-let is_model proc_name = List.mem dispatch_models ~equal:String.equal (Procname.to_string proc_name)

infer/src/biabduction/SymExec.ml

@@ -1077,11 +1077,6 @@ let declare_locals_and_ret tenv pdesc (prop_ : Prop.normal Prop.t) =
   prop'
 
 
-let get_closure_opt actual_params =
-  List.find_map actual_params ~f:(fun (exp, _) ->
-      match exp with Exp.Closure c when Procname.is_objc_block c.name -> Some c | _ -> None )
-
-
 (** Execute [instr] with a symbolic heap [prop].*)
 let rec sym_exec
     ( {InterproceduralAnalysis.proc_desc= current_pdesc; analyze_dependency; err_log; tenv} as
@@ -1109,12 +1104,9 @@ let rec sym_exec
               let par' = List.map ~f:(fun (id_exp, _, typ, _) -> (id_exp, typ)) c.captured_vars in
               Sil.Call (ret, proc_exp', par' @ par, loc, call_flags)
           | Exp.Const (Const.Cfun callee_pname) when ObjCDispatchModels.is_model callee_pname -> (
-            match get_closure_opt par with
+            match ObjCDispatchModels.get_dispatch_closure_opt par with
-            | Some c ->
+            | Some (cname, args) ->
-                (* We assume that for these modelled functions, the block passed as parameter doesn't
+                Sil.Call (ret, Exp.Const (Const.Cfun cname), args, loc, call_flags)
-                   have arguments, so we only pass the captured variables. *)
-                let args = List.map ~f:(fun (id_exp, _, typ, _) -> (id_exp, typ)) c.captured_vars in
-                Sil.Call (ret, Exp.Const (Const.Cfun c.name), args, loc, call_flags)
             | None ->
                 Sil.Call (ret, exp', par, loc, call_flags) )
           | _ ->