Skipping reporting global variable warning on known non-expensive cases.

Reviewed By: dulmarod

Differential Revision: D3298191

fbshipit-source-id: 8b3a38b

facebook-clang-plugins

@@ -1 +1 @@
-Subproject commit f5c1bd411f95ba797e0e0e5c15a562d91eb6a6c9
+Subproject commit ba3d4b9066cc57c413581d2efe909add94b4366f

infer/src/clang/ast_expressions.ml

@@ -55,6 +55,7 @@ let empty_var_decl_info = {
   vdi_is_static_local = false;
   vdi_is_module_private = false;
   vdi_is_nrvo_variable = false;
+  vdi_is_const_expr = false;
   vdi_init_expr = None;
   vdi_parm_index_in_function = None;
 }

infer/src/clang/cFrontend_checkers.ml

@@ -59,12 +59,33 @@ let rec is_self s =
        | _ -> false)
   | _ -> false
 
-let is_function_or_method_call _ st =
+let decl_ref_is_in names st =
   match st with
-  | Clang_ast_t.CallExpr _  (* for C *)
+  | Clang_ast_t.DeclRefExpr (_, _, _, drti) ->
+      (match drti.drti_decl_ref with
+       | Some dr -> let ndi, _, _ = CFrontend_utils.Ast_utils.get_info_from_decl_ref dr in
+           IList.exists (fun n -> n = ndi.ni_name) names
+       | _ -> false)
+  | _ -> false
+
+let call_function_named st names =
+  Ast_utils.exists_eventually_st decl_ref_is_in names st
+
+let rec eventually_makes_a_call exp =
+  CFrontend_utils.Ast_utils.exists_eventually_st is_expensive_function_or_method_call () exp
+
+and is_expensive_function_or_method_call _ st =
+  let white_list_functions = ["CGPointMake"] in
+  let open Clang_ast_t in
+  match st with
+  | CallExpr (_, st :: _, _) -> (* for C *)
+      not (call_function_named st white_list_functions)
+  | CXXConstructExpr (_, stmt_list, _, _) ->
+      (* Assumption: constructor is expensive iff it has a call inside *)
+      (IList.exists eventually_makes_a_call) stmt_list
+  | CXXTemporaryObjectExpr _ (* for C++ *)
   | CXXMemberCallExpr _ | CXXOperatorCallExpr _
-  | CXXConstructExpr _ | CXXTemporaryObjectExpr _ (* for C++ *)
+  | ObjCMessageExpr _ -> true (* for ObjC *)
-  | Clang_ast_t.ObjCMessageExpr _ -> true (* for ObjC *)
   | _ -> false
 
 (* Call method m and on the pn parameter pred holds *)
@@ -88,17 +109,15 @@ let dec_body_eventually atomic_pred param dec =
 
 (* true if a variable is initialized with a method/function call.*)
 (* implemented as decl |= EF is_function_or_method_call *)
-let is_initialized_with_call decl =
+let is_initialized_with_expensive_call decl =
   match decl with
   | Clang_ast_t.VarDecl (_, _ ,_, vdi) ->
       (match vdi.vdi_init_expr with
        | Some init_expr ->
-           CFrontend_utils.Ast_utils.exists_eventually_st is_function_or_method_call () init_expr
+           eventually_makes_a_call init_expr
        | _ -> false)
   | _ -> false
 
-
-
 (* === Warnings on properties === *)
 
 (* Assing Pointer Warning: a property with a pointer type should not be declared `assign` *)
@@ -149,7 +168,8 @@ let global_var_init_with_calls_warning decl =
     | None -> assert false (* we cannot be here *) in
   let condition = (CFrontend_utils.Ast_utils.is_objc () || CFrontend_utils.Ast_utils.is_objcpp ())
                   && CFrontend_utils.Ast_utils.is_global_var decl
-                  && is_initialized_with_call decl in
+                  && (not (CFrontend_utils.Ast_utils.is_const_expr_var decl))
+                  && is_initialized_with_expensive_call decl in
   if condition then
     Some {
       name = "GLOBAL_VARIABLE_INITIALIZED_WITH_FUNCTION_OR_METHOD_CALL";

infer/src/clang/cFrontend_utils.ml

@@ -404,6 +404,11 @@ struct
     | Clang_ast_t.VarDecl (_, _ ,_, vdi) -> vdi.vdi_is_global
     | _ -> false
 
+  let is_const_expr_var decl =
+    match decl with
+    | Clang_ast_t.VarDecl (_, _ ,_, vdi) -> vdi.vdi_is_const_expr
+    | _ -> false
+
   let is_objc () =
     match Config.clang_lang with
     | Config.OBJC -> true

infer/src/clang/cFrontend_utils.mli

@@ -138,6 +138,9 @@ sig
   (* true if a declaration is a global variable *)
   val is_global_var : Clang_ast_t.decl -> bool
 
+  (* true if a declaration is a constexpr variable *)
+  val is_const_expr_var : Clang_ast_t.decl -> bool
+
   (* true if CFrontend_config.language is set ot ObjC *)
   val is_objc : unit -> bool
 

infer/tests/codetoanalyze/objcpp/frontend/global-var/B.mm

@@ -7,7 +7,8 @@
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
-#import <Foundation/NSObject.h>
+#import <Foundation/Foundation.h>
+#import <CoreGraphics/CoreGraphics.h>
 
 @interface A : NSObject
 + (int)bar;
@@ -34,6 +35,19 @@ static const float kLineSize = 1 / [A scale]; // Error
 
 static const float ok = 37;
 
+const NSRange NSNotFoundRange =
+    (NSRange){.location = NSNotFound, .length = 0}; // OK
+
+const static CFRange FBCFNotFoundRange =
+    (CFRange){.location = kCFNotFound, .length = 7}; // OK
+
+const CGPoint offset = CGPointMake(0, 0); // OK
+
+constexpr double square(double x) { return x * x; }
+
+const int dmv = 17;
+constexpr double max1 = 1.4 * square(dmv); // OK
+
 void bla() {
   static const int kInsets = foo(); // Error
 

infer/tests/endtoend/objcpp/GlobalVarTest.java

@@ -7,7 +7,7 @@
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
-package endtoend.objc;
+package endtoend.objcpp;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static utils.matchers.ResultContainsLineNumbers.containsLines;
@@ -52,7 +52,7 @@ public class GlobalVarTest {
     assertThat(
         "Results should contain " + GLOBAL_VARIABLE_INITIALIZED_WITH_FUNCTION_OR_METHOD_CALL,
         inferResults,
-        containsLines(new int[]{29, 31, 33}));
+        containsLines(new int[]{30, 32, 34}));
   }
 
 }

infer/tests/utils/InferRunner.java

@@ -195,6 +195,9 @@ public class InferRunner {
       case CPP:
         stdParam = "-std=c++11";
         break;
+      case ObjCPP:
+        stdParam = "-std=c++11";
+        break;
     }
     return stdParam;
   }