Getting a more precise type when creating ObjC objects

Reviewed By: ddino

Differential Revision: D3282402

fbshipit-source-id: 4a57c9c

infer/src/IR/attributesTable.ml

@@ -49,3 +49,25 @@ let store_attributes proc_attributes =
 let load_attributes proc_name =
   let attributes_file = res_dir_attr_filename proc_name in
   Serialization.from_file serializer attributes_file
+
+(** Given a procdesure name, find the file where it is defined and *)
+(** its corresponding type environment *)
+let find_tenv_from_class_of_proc procname =
+  match load_attributes procname with
+  | None -> None
+  | Some attrs ->
+      let source_file = attrs.ProcAttributes.loc.Location.file in
+      let source_dir = DB.source_dir_from_source_file source_file in
+      let tenv_fname = DB.source_dir_get_internal_file source_dir ".tenv" in
+      Tenv.load_from_file tenv_fname
+
+(** Given an ObjC class c, extract the type from the tenv where the class was *)
+(** defined. We do this by adding a method that is unique to each class, and then *)
+(** finding the tenv that corresponds to the class definition.  *)
+let get_correct_type_from_objc_class_name c =
+  let class_method = Procname.get_default_objc_class_method (Mangled.to_string c) in
+  match find_tenv_from_class_of_proc class_method with
+  | None -> None
+  | Some tenv ->
+      let type_name = Typename.TN_csu (Csu.Class Csu.Objc, c) in
+      Option.map (fun st -> Sil.Tstruct st) (Tenv.lookup tenv type_name)

infer/src/IR/attributesTable.mli

@@ -17,3 +17,12 @@ val store_attributes : ProcAttributes.t -> unit
 
 (** Load the attributes for the procedure from the attributes database. *)
 val load_attributes : Procname.t -> ProcAttributes.t option
+
+(** Given a procdesure name, find the file where it is defined and *)
+(** its corresponding type environment *)
+val find_tenv_from_class_of_proc : Procname.t -> Tenv.t option
+
+(** Given an ObjC class c, extract the type from the tenv where the class was *)
+(** defined. We do this by adding a method that is unique to each class, and then *)
+(** finding the tenv that corresponds to the class definition.  *)
+val get_correct_type_from_objc_class_name : Mangled.t -> Sil.typ option

infer/src/IR/procname.ml

@@ -182,6 +182,10 @@ let objc_cpp class_name method_name mangled =
     mangled = mangled;
   }
 
+let get_default_objc_class_method objc_class =
+  let objc_cpp = objc_cpp objc_class "__find_class_" (Some "internal") in
+  ObjC_Cpp objc_cpp
+
 (** Create an objc procedure name from a class_name and method_name. *)
 let mangled_objc_block name =
   Block name

infer/src/IR/procname.mli

@@ -108,6 +108,8 @@ val mangled_of_objc_method_kind : objc_method_kind -> string option
 (** Create an objc procedure name from a class_name and method_name. *)
 val objc_cpp : string -> string -> string option -> objc_cpp
 
+val get_default_objc_class_method : string -> t
+
 (** Get the class name of a Objective-C/C++ procedure name. *)
 val objc_cpp_get_class_name : objc_cpp -> string
 

infer/src/backend/modelBuiltins.ml

@@ -770,6 +770,13 @@ let execute_alloc mk can_return_null
   let handle_sizeof_exp size_exp =
     Sil.Sizeof (Sil.Tarray (Sil.Tint Sil.IChar, size_exp), Sil.Subtype.exact) in
   let size_exp, procname = match args with
+    | [(Sil.Sizeof (Sil.Tstruct
+                      { Sil.csu = Csu.Class Csu.Objc; struct_name = Some c } as s, subt), _)] ->
+        let struct_type =
+          match AttributesTable.get_correct_type_from_objc_class_name c with
+          | Some struct_type -> struct_type
+          | None -> s in
+        Sil.Sizeof (struct_type, subt), pname
     | [(size_exp, _)] -> (* for malloc and __new *)
         size_exp, Sil.mem_alloc_pname mk
     | [(size_exp, _); (Sil.Const (Sil.Cfun pname), _)] ->

infer/src/clang/cFrontend_decl.ml

@@ -166,10 +166,12 @@ struct
            ignore (ObjcCategory_decl.category_impl_decl CTypes_decl.type_ptr_to_sil_type tenv dec);
            process_methods tenv cg cfg curr_class decl_list;
 
-       | ObjCImplementationDecl(_, _, decl_list, _, idi) ->
+       | ObjCImplementationDecl(decl_info, _, decl_list, _, idi) ->
            let curr_class = ObjcInterface_decl.get_curr_class_impl idi in
+           let class_name = CContext.get_curr_class_name curr_class in
            let type_ptr_to_sil_type = CTypes_decl.type_ptr_to_sil_type in
            ignore (ObjcInterface_decl.interface_impl_declaration type_ptr_to_sil_type tenv dec);
+           CMethod_trans.add_default_method_for_class class_name decl_info;
            process_methods tenv cg cfg curr_class decl_list;
 
        | CXXMethodDecl (decl_info, _, _, _, _)

infer/src/clang/cMethod_trans.ml

@@ -462,6 +462,12 @@ let get_method_for_frontend_checks cfg cg loc =
       Cg.add_defined_node cg proc_name;
       pdesc
 
+let add_default_method_for_class class_name decl_info =
+  let loc = CLocation.get_sil_location_from_range decl_info.Clang_ast_t.di_source_range true in
+  let proc_name = Procname.get_default_objc_class_method class_name in
+  let attrs = { (ProcAttributes.default proc_name Config.C_CPP) with loc = loc; } in
+  AttributesTable.store_attributes attrs
+
 let get_procname_from_cpp_lambda context dec =
   match dec with
   | Clang_ast_t.CXXRecordDecl (_, _, _, _, _, _, _, cxx_rdi) ->

infer/src/clang/cMethod_trans.mli

@@ -52,4 +52,6 @@ val create_procdesc_with_pointer : CContext.t -> Clang_ast_t.pointer -> string o
 
 val get_method_for_frontend_checks : Cfg.cfg -> Cg.t -> Location.t -> Cfg.Procdesc.t
 
+val add_default_method_for_class : string -> Clang_ast_t.decl_info -> unit
+
 val get_procname_from_cpp_lambda : CContext.t -> Clang_ast_t.decl -> Procname.t