[linters] Do not lint implicit declarations

Reviewed By: ddino

Differential Revision: D6009056

fbshipit-source-id: e69f566

infer/lib/linter_rules/linters.al

@@ -254,5 +254,5 @@ DEFINE-CHECKER POINTER_TO_CONST_OBJC_CLASS = {
   SET suggestion = "Consider using `%class_name% *const` instead, meaning
 	                  the destination of the pointer cannot be changed.";
   SET severity = "WARNING";
-  SET mode = "OFF";
+  SET mode = "ON";
 };

infer/src/clang/cAst_utils.ml

@@ -507,3 +507,7 @@ let has_block_attribute decl =
       List.exists ~f:(fun attr -> match attr with BlocksAttr _ -> true | _ -> false) attributes
   | _
    -> false
+
+let is_implicit_decl decl =
+  let decl_info = Clang_ast_proj.get_decl_tuple decl in
+  decl_info.Clang_ast_t.di_is_implicit

infer/src/clang/cAst_utils.mli

@@ -153,3 +153,5 @@ val get_cxx_virtual_base_classes : Clang_ast_t.decl -> Clang_ast_t.type_ptr list
 val is_std_vector : Clang_ast_t.qual_type -> bool
 
 val has_block_attribute : Clang_ast_t.decl -> bool
+
+val is_implicit_decl : Clang_ast_t.decl -> bool

infer/src/clang/cFrontend_checkers_main.ml

@@ -280,6 +280,8 @@ and do_frontend_checks_via_transition context map_active an trans =
 and do_frontend_checks_decl (context: CLintersContext.context)
     (map_act: Tableaux.context_linter_map) decl =
   let open Clang_ast_t in
+  if CAst_utils.is_implicit_decl decl then () (* do not analyze implicit declarations *)
+  else
     let an = Ctl_parser_types.Decl decl in
     (* The map should be visited when we enter the node before visiting children *)
     let map_active = Tableaux.update_linter_context_map an map_act in

infer/tests/codetoanalyze/objc/linters/issues.exp

@@ -1,5 +1,3 @@
-codetoanalyze/objc/linters/Pointer_to_const_objc_class.m, C_ptr_to_const_objc_bad, 13, POINTER_TO_CONST_OBJC_CLASS, []
-codetoanalyze/objc/linters/Pointer_to_const_objc_class.m, C_setPtr_to_const_objc_bad, 13, POINTER_TO_CONST_OBJC_CLASS, []
 codetoanalyze/objc/linters/Pointer_to_const_objc_class.m, Linters_dummy_method, 13, POINTER_TO_CONST_OBJC_CLASS, []
 codetoanalyze/objc/linters/assign_pointer.m, Linters_dummy_method, 18, ASSIGN_POINTER_WARNING, []
 codetoanalyze/objc/linters/assign_pointer.m, Linters_dummy_method, 20, ASSIGN_POINTER_WARNING, []