[frontend] Refactoring for the following diff

Summary:
This diff does refactoring for the following diff.

* Define Mangled.return_param and Mangled.is_return_param and use it instead of
  Ident.name_return_param.
* Share common code from objc_setter and objc_getter
* Move struct_copy to CStructUtils.ml

Reviewed By: da319

Differential Revision: D27940125

fbshipit-source-id: 84eb3109b

infer/src/IR/Ident.ml

@@ -156,9 +156,6 @@ end
 (** Name used for the return variable *)
 let name_return = Mangled.from_string "return"
 
-(** Name used for the return param variable *)
-let name_return_param = Mangled.from_string "__return_param"
-
 (** Return the standard name for the given kind *)
 let standard_name kind =
   if equal_kind kind KNormal || equal_kind kind KNone then Name.Normal

infer/src/IR/Ident.mli

@@ -69,9 +69,6 @@ val name_spec : name
 val name_return : Mangled.t
 (** Name used for the return variable *)
 
-val name_return_param : Mangled.t
-(** Name used for the return param variable *)
-
 val string_to_name : string -> name
 (** Convert a string to a name. *)
 

infer/src/IR/Mangled.ml

@@ -42,6 +42,10 @@ let self = from_string "self"
 
 let is_self = function {plain= "self"} -> true | _ -> false
 
+let return_param = from_string "__return_param"
+
+let is_return_param = function {plain= "__return_param"} -> true | _ -> false
+
 module Set = PrettyPrintable.MakePPSet (struct
   type nonrec t = t [@@deriving compare]
 

infer/src/IR/Mangled.mli

@@ -39,6 +39,10 @@ val self : t [@@warning "-32"]
 
 val is_self : t -> bool
 
+val return_param : t
+
+val is_return_param : t -> bool
+
 (** Set of Mangled. *)
 module Set : PrettyPrintable.PPSet with type elt = t
 

infer/src/IR/Pvar.ml

@@ -236,7 +236,7 @@ let mk (name : Mangled.t) (proc_name : Procname.t) : t =
 
 let get_ret_pvar pname = mk Ident.name_return pname
 
-let get_ret_param_pvar pname = mk Ident.name_return_param pname
+let get_ret_param_pvar pname = mk Mangled.return_param pname
 
 (** [mk_callee name proc_name] creates a program var for a callee function with the given function
     name *)

infer/src/clang/CAddImplicitGettersSetters.ml

@@ -7,39 +7,47 @@
 
 open! IStd
 
-let objc_getter proc_desc location (self_var, self_typ) (fieldname, field_typ, _) =
-  let id_pvar = Ident.create_fresh Ident.knormal in
-  let load_pvar_instr =
-    Sil.Load {id= id_pvar; e= Lvar self_var; root_typ= self_typ; typ= self_typ; loc= location}
+let get_load_self_instr location (self, self_typ) fieldname =
+  let id_self = Ident.create_fresh Ident.knormal in
+  let load_self_instr =
+    Sil.Load {id= id_self; e= Lvar self; root_typ= self_typ; typ= self_typ; loc= location}
   in
-  let id_field = Ident.create_fresh Ident.knormal in
   let class_typ = match self_typ.Typ.desc with Typ.Tptr (t, _) -> t | _ -> self_typ in
-  let e = Exp.Lfield (Var id_pvar, fieldname, class_typ) in
+  let field_exp = Exp.Lfield (Var id_self, fieldname, class_typ) in
+  (field_exp, load_self_instr)
+
+
+let objc_getter proc_desc location self_with_typ (fieldname, field_typ, _) =
+  let field_exp, load_self_instr = get_load_self_instr location self_with_typ fieldname in
+  let store_instrs =
+    let id_field = Ident.create_fresh Ident.knormal in
     let load_field_instr =
-    Sil.Load {id= id_field; e; root_typ= field_typ; typ= field_typ; loc= location}
+      Sil.Load {id= id_field; e= field_exp; root_typ= field_typ; typ= field_typ; loc= location}
     in
     let exp_var = Exp.Lvar (Procdesc.get_ret_var proc_desc) in
     let return_exp =
-    Sil.Store {e1= exp_var; root_typ= field_typ; typ= field_typ; e2= Exp.Var id_field; loc= location}
+      Sil.Store
+        {e1= exp_var; root_typ= field_typ; typ= field_typ; e2= Exp.Var id_field; loc= location}
+    in
+    [load_field_instr; return_exp]
   in
-  [load_pvar_instr; load_field_instr; return_exp]
+  load_self_instr :: store_instrs
 
 
-let objc_setter location (self, self_typ) (var, var_typ) (fieldname, field_typ, _) =
-  let id_self = Ident.create_fresh Ident.knormal in
-  let load_self_instr =
-    Sil.Load {id= id_self; e= Lvar self; root_typ= self_typ; typ= self_typ; loc= location}
-  in
-  let id_var = Ident.create_fresh Ident.knormal in
+let objc_setter location self_with_typ (var, var_typ) (fieldname, field_typ, _) =
+  let field_exp, load_self_instr = get_load_self_instr location self_with_typ fieldname in
+  let store_instrs =
+    let id_field = Ident.create_fresh Ident.knormal in
     let load_var_instr =
-    Sil.Load {id= id_var; e= Lvar var; root_typ= var_typ; typ= var_typ; loc= location}
+      Sil.Load {id= id_field; e= Lvar var; root_typ= var_typ; typ= var_typ; loc= location}
     in
-  let class_typ = match self_typ.Typ.desc with Typ.Tptr (t, _) -> t | _ -> self_typ in
-  let field_exp = Exp.Lfield (Var id_self, fieldname, class_typ) in
     let store_exp =
-    Sil.Store {e1= field_exp; root_typ= field_typ; typ= field_typ; e2= Exp.Var id_var; loc= location}
+      Sil.Store
+        {e1= field_exp; root_typ= field_typ; typ= field_typ; e2= Exp.Var id_field; loc= location}
+    in
+    [load_var_instr; store_exp]
   in
-  [load_self_instr; load_var_instr; store_exp]
+  load_self_instr :: store_instrs
 
 
 let process_getter_setter proc_name proc_desc =

infer/src/clang/CStructUtils.ml

@@ -0,0 +1,26 @@
+(*
+ * 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 struct_copy tenv loc e1 e2 ~typ ~struct_name =
+  let rec struct_copy_helper e1 e2 typ struct_name rev_acc =
+    let {Struct.fields} = Option.value_exn (Tenv.lookup tenv struct_name) in
+    List.fold fields ~init:rev_acc ~f:(fun rev_acc (field_name, field_typ, _) ->
+        let mk_field e = Exp.Lfield (e, field_name, typ) in
+        let e1 = mk_field e1 in
+        let e2 = mk_field e2 in
+        match field_typ.Typ.desc with
+        | Tstruct (CStruct _ as struct_name) ->
+            struct_copy_helper e1 e2 field_typ struct_name rev_acc
+        | _ ->
+            let id = Ident.create_fresh Ident.knormal in
+            Sil.Store {e1; root_typ= field_typ; typ= field_typ; e2= Exp.Var id; loc}
+            :: Sil.Load {id; e= e2; root_typ= field_typ; typ= field_typ; loc}
+            :: rev_acc )
+  in
+  if Exp.equal e1 e2 then [] else struct_copy_helper e1 e2 typ struct_name [] |> List.rev

infer/src/clang/CStructUtils.mli

@@ -0,0 +1,11 @@
+(*
+ * 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
+
+val struct_copy :
+  Tenv.t -> Location.t -> Exp.t -> Exp.t -> typ:Typ.t -> struct_name:Typ.name -> Sil.instr list

infer/src/clang/cTrans.ml

@@ -986,25 +986,6 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
     mk_trans_result (array_exp, typ) control
 
 
-  and struct_copy tenv loc e1 e2 typ struct_name =
-    let rec struct_copy_helper e1 e2 typ struct_name rev_acc =
-      let {Struct.fields} = Option.value_exn (Tenv.lookup tenv struct_name) in
-      List.fold fields ~init:rev_acc ~f:(fun rev_acc (field_name, field_typ, _) ->
-          let mk_field e = Exp.Lfield (e, field_name, typ) in
-          let e1 = mk_field e1 in
-          let e2 = mk_field e2 in
-          match field_typ.Typ.desc with
-          | Tstruct (CStruct _ as struct_name) ->
-              struct_copy_helper e1 e2 field_typ struct_name rev_acc
-          | _ ->
-              let id = Ident.create_fresh Ident.knormal in
-              Sil.Store {e1; root_typ= field_typ; typ= field_typ; e2= Exp.Var id; loc}
-              :: Sil.Load {id; e= e2; root_typ= field_typ; typ= field_typ; loc}
-              :: rev_acc )
-    in
-    if Exp.equal e1 e2 then [] else struct_copy_helper e1 e2 typ struct_name [] |> List.rev
-
-
   and binaryOperator_trans trans_state binary_operator_info stmt_info expr_info stmt_list =
     L.debug Capture Verbose "  BinaryOperator '%a' "
       (Pp.of_string ~f:Clang_ast_j.string_of_binary_operator_kind)
@@ -1029,8 +1010,8 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
           (instruction trans_state' s1, instruction trans_state' s2)
         in
         let instrs =
-          struct_copy context.CContext.tenv sil_loc (fst res_trans_e1.return)
-            (fst res_trans_e2.return) res_typ struct_name
+          CStructUtils.struct_copy context.CContext.tenv sil_loc (fst res_trans_e1.return)
+            (fst res_trans_e2.return) ~typ:res_typ ~struct_name
         in
         [res_trans_e1.control; res_trans_e2.control; {empty_control with instrs}]
         |> PriorityNode.compute_controls_to_parent trans_state_pri sil_loc node_name stmt_info
@@ -2643,7 +2624,8 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
         let instrs =
           match cstruct_name_opt with
           | Some struct_name ->
-              struct_copy context.CContext.tenv sil_loc var_exp sil_e1' var_typ struct_name
+              CStructUtils.struct_copy context.CContext.tenv sil_loc var_exp sil_e1' ~typ:var_typ
+                ~struct_name
           | None ->
               [Sil.Store {e1= var_exp; root_typ= ie_typ; typ= ie_typ; e2= sil_e1'; loc= sil_loc}]
         in
@@ -3033,8 +3015,8 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
       , Some {desc= Tptr ({desc= Tstruct (CStruct _ as struct_name)}, _)} ) ->
         (* return (exp:struct); *)
         return_stmt stmt ~mk_ret_instrs:(fun ret_exp _root_typ ret_typ res_trans_stmt ->
-            struct_copy context.CContext.tenv sil_loc ret_exp (fst res_trans_stmt.return) ret_typ
-              struct_name )
+            CStructUtils.struct_copy context.CContext.tenv sil_loc ret_exp
+              (fst res_trans_stmt.return) ~typ:ret_typ ~struct_name )
     | [stmt], _ ->
         (* return exp; *)
         return_stmt stmt ~mk_ret_instrs:(fun ret_exp root_typ ret_typ res_trans_stmt ->

infer/src/pulse/PulseObjectiveCSummary.ml

@@ -44,8 +44,7 @@ let mk_objc_method_nil_summary_aux tenv proc_desc astate =
   let* astate, self_value = PulseOperations.eval_deref location (Lvar self) astate in
   let* astate = PulseArithmetic.prune_eq_zero (fst self_value) astate in
   match List.last (Procdesc.get_formals proc_desc) with
-  | Some (last_formal, {desc= Tptr (typ, _)}) when Mangled.equal last_formal Ident.name_return_param
-    ->
+  | Some (last_formal, {desc= Tptr (typ, _)}) when Mangled.is_return_param last_formal ->
       let ret_param_var = Procdesc.get_ret_param_var proc_desc in
       let* astate, ret_param_var_addr_hist =
         PulseOperations.eval_deref location (Lvar ret_param_var) astate