Split get_super into get_super_impl and get_super_if

Reviewed By: jvillard

Differential Revision: D3693879

fbshipit-source-id: b18f930

infer/src/clang/cFrontend_checkers.ml

@@ -334,7 +334,7 @@ let checker_NSNotificationCenter _ decl_info impl_decl_info decls =
     match super with
     | Some (decl_list, impl_decl_info) ->
         (f decl_list
-         || exists_on_hierarchy f (Ast_utils.get_super impl_decl_info))
+         || exists_on_hierarchy f (Ast_utils.get_super_impl impl_decl_info))
     | None -> false in
 
   let eventually_removeObserver_in_whole_hierarchy decls impl_decl_info =

infer/src/clang/cFrontend_utils.ml

@@ -469,15 +469,25 @@ struct
     Buffer.add_string buffer name;
     Buffer.contents buffer
 
-  let get_super impl_decl_info =
+  let rec get_super_if decl =
+    match decl with
+    | Some Clang_ast_t.ObjCImplementationDecl(_, _, _, _, impl_decl_info) ->
+        (* Try getting the super ref through the impl info, and fall back to
+           getting the if decl first and getting the super ref through it. *)
+        let super_ref = get_decl_opt_with_decl_ref impl_decl_info.oidi_super in
+        if Option.is_some super_ref then
+          super_ref
+        else
+          get_super_if (get_decl_opt_with_decl_ref impl_decl_info.oidi_class_interface)
+    | Some Clang_ast_t.ObjCInterfaceDecl(_, _, _, _, interface_decl_info) ->
+        get_decl_opt_with_decl_ref interface_decl_info.otdi_super
+    | _ -> None
+
+  let get_super_impl impl_decl_info =
     let objc_interface_decl_current =
       get_decl_opt_with_decl_ref
         impl_decl_info.Clang_ast_t.oidi_class_interface in
-    let objc_interface_decl_super =
+    let objc_interface_decl_super = get_super_if objc_interface_decl_current in
-      match objc_interface_decl_current with
-      | Some Clang_ast_t.ObjCInterfaceDecl(_, _, _, _, interface_decl_info) ->
-          get_decl_opt_with_decl_ref interface_decl_info.otdi_super
-      | _ -> None in
     let objc_implementation_decl_super =
       match objc_interface_decl_super with
       | Some ObjCInterfaceDecl(_, _, _, _, interface_decl_info) ->

infer/src/clang/cFrontend_utils.mli

@@ -159,11 +159,15 @@ sig
   (* Generates a key for a declaration based on its name and the declaration tag. *)
   val generate_key_decl : Clang_ast_t.decl -> string
 
+  (* Given an objc impl or interface decl, returns the objc interface decl of
+     the superclass, if any. *)
+  val get_super_if : Clang_ast_t.decl option -> Clang_ast_t.decl option
+
   (*
    * Given an objc impl decl info, return the super class's list of decls and
    * its objc impl decl info.
    *)
-  val get_super :
+  val get_super_impl :
     Clang_ast_t.obj_c_implementation_decl_info ->
     (Clang_ast_t.decl list *
      Clang_ast_t.obj_c_implementation_decl_info)