[clang] use a more efficient `var_decl_info`

Summary:
Update plugin to take into account that some fields of VarDecl were unused by
infer. Also, use a boolean holding `hasExternalStorage` instead of comparing to
the fragile (and probably not entirely accurate) `"extern"` string.

update-submodule: facebook-clang-plugins

Reviewed By: mbouaziz

Differential Revision: D6231836

fbshipit-source-id: 3c0a75b

facebook-clang-plugins

@@ -1 +1 @@
-Subproject commit 4274a6ac7a43a91d7296f6bbf2d1a2634a5ca443
+Subproject commit 00a64caee5877d6cd23816776b8ed56c704f376e

infer/src/clang/cFrontend_config.ml

@@ -151,8 +151,6 @@ let return_param = "__return_param"
 
 let self = "self"
 
-let static = "static"
-
 let std_addressof = QualifiedCppName.Match.of_fuzzy_qual_names ["std::addressof"]
 
 let string_with_utf8_m = "stringWithUTF8String:"

infer/src/clang/cFrontend_config.mli

@@ -148,8 +148,6 @@ val return_param : string
 
 val self : string
 
-val static : string
-
 val std_addressof : QualifiedCppName.Match.quals_matcher
 
 val string_with_utf8_m : string

infer/src/clang/cGeneral_utils.ml

@@ -70,14 +70,6 @@ let rec collect_list_tuples l (a, a1, b, c, d) =
       collect_list_tuples l' (a @ a', a1 @ a1', b @ b', c @ c', d @ d')
 
 
-let is_static_var var_decl_info =
-  match var_decl_info.Clang_ast_t.vdi_storage_class with
-  | Some sc ->
-      String.equal sc CFrontend_config.static
-  | _ ->
-      false
-
-
 let rec zip xs ys =
   match (xs, ys) with [], _ | _, [] -> [] | x :: xs, y :: ys -> (x, y) :: zip xs ys
 
@@ -136,15 +128,15 @@ let mk_sil_global_var {CFrontend_config.source_file} ?(mk_name= fun _ x -> x) na
     var_decl_info qt =
   let name_string, simple_name = get_var_name_mangled named_decl_info var_decl_info in
   let translation_unit =
-    match Clang_ast_t.((var_decl_info.vdi_storage_class, var_decl_info.vdi_init_expr)) with
+    match Clang_ast_t.((var_decl_info.vdi_is_extern, var_decl_info.vdi_init_expr)) with
-    | Some "extern", None ->
+    | true, None ->
-        (* some compilers simply disregard "extern" when the global is given some initialisation
-           code, which is why we make sure that [vdi_init_expr] is None here... *)
         Pvar.TUExtern
     | _, None when var_decl_info.Clang_ast_t.vdi_is_static_data_member ->
         (* non-const static data member get extern scope unless they are defined out of line here (in which case vdi_init_expr will not be None) *)
         Pvar.TUExtern
-    | _ ->
+    | true, Some _
+    (* "extern" variables with initialisation code are not extern at all, but compilers accept this *)
+    | false, _ ->
         Pvar.TUFile source_file
   in
   let is_constexpr = var_decl_info.Clang_ast_t.vdi_is_const_expr in

infer/src/clang/cGeneral_utils.mli

@@ -26,8 +26,6 @@ val collect_list_tuples :
 
 val swap_elements_list : 'a list -> 'a list
 
-val is_static_var : Clang_ast_t.var_decl_info -> bool
-
 val zip : 'a list -> 'b list -> ('a * 'b) list
 
 val list_range : int -> int -> int list