[linters] Do not report MUTABLE_LOCAL_VARIABLE_IN_COMPONENT_FILE for the loop indices

Reviewed By: jvillard

Differential Revision: D5964060

fbshipit-source-id: 5998eff

infer/src/clang/CLintersContext.ml

@@ -25,7 +25,8 @@ type context =
         (** If inside an objc class, contains the objc class (impl or interface) decl. *)
   ; current_objc_class: Clang_ast_t.decl option
   ; et_evaluation_node: string option
-  ; if_context: if_context option }
+  ; if_context: if_context option
+  ; in_for_loop_declaration: bool }
 
 let empty translation_unit_context =
   { current_method= None
@@ -35,7 +36,8 @@ let empty translation_unit_context =
   ; is_ck_translation_unit= false
   ; current_objc_class= None
   ; et_evaluation_node= None
-  ; if_context= None }
+  ; if_context= None
+  ; in_for_loop_declaration= false }
 
 let add_parent_method decl_opt parent_methods =
   match decl_opt with Some decl -> decl :: parent_methods | None -> parent_methods

infer/src/clang/CLintersContext.mli

@@ -25,7 +25,8 @@ type context =
         (** If inside an objc class, contains the objc class (impl or interface) decl. *)
   ; current_objc_class: Clang_ast_t.decl option
   ; et_evaluation_node: string option
-  ; if_context: if_context option }
+  ; if_context: if_context option
+  ; in_for_loop_declaration: bool }
 
 val empty : CFrontend_config.translation_unit_context -> context
 

infer/src/clang/ComponentKit.ml

@@ -126,6 +126,7 @@ let mutable_local_vars_advice context an =
         is_ck_context context an && not (CAst_utils.is_syntactically_global_var decl)
         && not (CAst_utils.is_static_local_var decl) && not is_const
         && not (is_of_whitelisted_type qual_type) && not decl_info.di_is_implicit
+        && not context.CLintersContext.in_for_loop_declaration
       in
       if condition then
         Some

infer/src/clang/cFrontend_checkers_main.ml

@@ -241,10 +241,11 @@ let rec do_frontend_checks_stmt (context: CLintersContext.context)
         (* distinguish between then and else branch as they need different context *)
         [ (context, [stmt1; stmt2; cond_stmt; inside_else_stmt])
         ; (inside_if_stmt_context, [inside_if_stmt]) ]
-    (* given that this has not been translated, looking up for variables *)
-    (* inside leads to inconsistencies *)
-    | ObjCAtCatchStmt _
-     -> [(context, [])]
+    | ForStmt (_, stmt1 :: stmts)
+     -> let inside_for_stmt_decl_context =
+          {context with CLintersContext.in_for_loop_declaration= true}
+        in
+        [(context, stmts); (inside_for_stmt_decl_context, [stmt1])]
     | _
      -> [(context, snd (Clang_ast_proj.get_stmt_tuple stmt))]
   in

infer/tests/build_systems/codetoanalyze/componentkit/TestIgnoreImports.mm

@@ -16,6 +16,9 @@
 @implementation SomeClass
 + (instancetype) new {
   int i; // error
+
+  for (int i = 0; i < 10; i++) {
+  }
   return nil;
 }
 @end