[linters] Remove unavailable api class false positives and turn it on

Summary:
This is a check for when an unavailable class is being allocated.

This diff also adds a check for the context to remove false positives: If the class is not available but the method calls are wrapped in a check whether the class is available, then don't report.

Reviewed By: jvillard

Differential Revision: D5631191

fbshipit-source-id: 2082dfe

infer/lib/linter_rules/linters.al

@@ -225,7 +225,10 @@ DEFINE-CHECKER CXX_REFERENCE_CAPTURED_IN_OBJC_BLOCK = {
 
 	DEFINE-CHECKER UNAVAILABLE_CLASS_IN_SUPPORTED_IOS_SDK = {
 		SET report_when =
-				 WHEN (class_unavailable_in_supported_ios_sdk())
+				 WHEN ((class_unavailable_in_supported_ios_sdk()) AND
+				       NOT within_available_class_block() AND
+							 (call_class_method(REGEXP(".*"), "alloc") OR
+							 call_class_method(REGEXP(".*"), "new")))
 				 HOLDS-IN-NODE ObjCMessageExpr;
 
 			SET message =
@@ -233,7 +236,7 @@ DEFINE-CHECKER CXX_REFERENCE_CAPTURED_IN_OBJC_BLOCK = {
 						 %iphoneos_target_sdk_version% (only available from version %class_available_ios_sdk%)";
 			SET name = "Unavailable API In Supported iOS SDK";
 			SET severity = "ERROR";
-			SET mode = "OFF";
+			SET mode = "ON";
 		};
 
 

infer/src/clang/CLintersContext.ml

@@ -9,7 +9,10 @@
 
 open! IStd
 
-type if_context = {within_responds_to_selector_block: string list; ios_version_guard: string list}
+type if_context =
+  { within_responds_to_selector_block: string list
+  ; within_available_class_block: string list
+  ; ios_version_guard: string list }
 
 type context =
   { translation_unit_context: CFrontend_config.translation_unit_context

infer/src/clang/cFrontend_checkers_main.ml

@@ -162,19 +162,33 @@ let rec get_current_os_version stmt =
 
 let compute_if_context (context: CLintersContext.context) stmt =
   let selector = get_responds_to_selector stmt in
+  let receiver_class_method_call =
+    match
+      (CPredicates.get_selector (Stmt stmt), CPredicates.receiver_class_method_call (Stmt stmt))
+    with
+    | Some selector, Some receiver when String.equal selector "class"
+     -> Option.to_list (CPredicates.declaration_name receiver)
+    | _
+     -> []
+  in
   let os_version = get_current_os_version stmt in
-  let within_responds_to_selector_block, ios_version_guard =
+  let within_responds_to_selector_block, within_available_class_block, ios_version_guard =
     match context.if_context with
     | Some if_context
      -> let within_responds_to_selector_block =
           List.append selector if_context.within_responds_to_selector_block
         in
+        let within_available_class_block =
+          List.append receiver_class_method_call if_context.within_available_class_block
+        in
         let ios_version_guard = List.append os_version if_context.ios_version_guard in
-        (within_responds_to_selector_block, ios_version_guard)
+        (within_responds_to_selector_block, within_available_class_block, ios_version_guard)
     | None
-     -> (selector, os_version)
+     -> (selector, receiver_class_method_call, os_version)
   in
-  Some ({within_responds_to_selector_block; ios_version_guard} : CLintersContext.if_context)
+  Some
+    ( {within_responds_to_selector_block; within_available_class_block; ios_version_guard}
+    : CLintersContext.if_context )
 
 let is_factory_method (context: CLintersContext.context) decl =
   let interface_decl_opt =

infer/src/clang/cPredicates.ml

@@ -29,12 +29,21 @@ let rec objc_class_of_pointer_type type_ptr =
   | _
    -> None
 
-let receiver_method_call an =
+let receiver_class_method_call an =
   match an with
-  | Ctl_parser_types.Stmt ObjCMessageExpr (_, args, _, obj_c_message_expr_info) -> (
+  | Ctl_parser_types.Stmt ObjCMessageExpr (_, _, _, obj_c_message_expr_info) -> (
     match obj_c_message_expr_info.omei_receiver_kind with
     | `Class qt
      -> CAst_utils.get_decl_from_typ_ptr qt.qt_type_ptr
+    | _
+     -> None )
+  | _
+   -> None
+
+let receiver_instance_method_call an =
+  match an with
+  | Ctl_parser_types.Stmt ObjCMessageExpr (_, args, _, obj_c_message_expr_info) -> (
+    match obj_c_message_expr_info.omei_receiver_kind with
     | `Instance -> (
       match args with
       | receiver :: _ -> (
@@ -50,6 +59,20 @@ let receiver_method_call an =
   | _
    -> None
 
+let receiver_method_call an =
+  match receiver_class_method_call an with
+  | Some decl
+   -> Some decl
+  | None
+   -> receiver_instance_method_call an
+
+let declaration_name decl =
+  match Clang_ast_proj.get_named_decl_tuple decl with
+  | Some (_, ndi)
+   -> Some ndi.ni_name
+  | None
+   -> None
+
 let get_available_attr_ios_sdk an =
   let open Clang_ast_t in
   let rec get_available_attr attrs =
@@ -137,11 +160,18 @@ let is_object_of_class_named receiver cname =
   | _
    -> false
 
-(* an |= call_method(m) where the name must be exactly m *)
-let call_method an m =
+let get_selector an =
   match an with
   | Ctl_parser_types.Stmt Clang_ast_t.ObjCMessageExpr (_, _, _, omei)
-   -> ALVar.compare_str_with_alexp omei.omei_selector m
+   -> Some omei.omei_selector
+  | _
+   -> None
+
+(* an |= call_method(m) where the name must be exactly m *)
+let call_method an m =
+  match get_selector an with
+  | Some selector
+   -> ALVar.compare_str_with_alexp selector m
   | _
    -> false
 
@@ -595,6 +625,19 @@ let within_responds_to_selector_block (cxt: CLintersContext.context) an =
   | _
    -> false
 
+let within_available_class_block (cxt: CLintersContext.context) an =
+  match (receiver_method_call an, cxt.if_context) with
+  | Some receiver, Some if_context
+   -> (
+      let in_available_class_block = if_context.within_available_class_block in
+      match declaration_name receiver with
+      | Some receiver_name
+       -> List.mem ~equal:String.equal in_available_class_block receiver_name
+      | None
+       -> false )
+  | _
+   -> false
+
 let objc_method_has_nth_parameter_of_type an _num _typ =
   let open Clang_ast_t in
   let num =

infer/src/clang/cPredicates.mli

@@ -21,6 +21,8 @@ val call_class_method : Ctl_parser_types.ast_node -> ALVar.alexp -> ALVar.alexp
 
 val call_instance_method : Ctl_parser_types.ast_node -> ALVar.alexp -> ALVar.alexp -> bool
 
+val declaration_name : Clang_ast_t.decl -> string option
+
 val is_enum_constant : Ctl_parser_types.ast_node -> ALVar.alexp -> bool
 
 val is_objc_interface_named : Ctl_parser_types.ast_node -> ALVar.alexp -> bool
@@ -85,6 +87,8 @@ val has_type_subprotocol_of : Ctl_parser_types.ast_node -> ALVar.alexp -> bool
 
 val get_available_attr_ios_sdk : Ctl_parser_types.ast_node -> string option
 
+val get_selector : Ctl_parser_types.ast_node -> string option
+
 val within_responds_to_selector_block :
   CLintersContext.context -> Ctl_parser_types.ast_node -> bool
 
@@ -93,6 +97,10 @@ val objc_method_has_nth_parameter_of_type :
 
 val using_namespace : Ctl_parser_types.ast_node -> ALVar.alexp -> bool
 
+val receiver_class_method_call : Ctl_parser_types.ast_node -> Clang_ast_t.decl option
+
+val receiver_instance_method_call : Ctl_parser_types.ast_node -> Clang_ast_t.decl option
+
 val receiver_method_call : Ctl_parser_types.ast_node -> Clang_ast_t.decl option
 
 val is_at_selector_with_name : Ctl_parser_types.ast_node -> ALVar.alexp -> bool
@@ -101,3 +109,5 @@ val is_at_selector_with_name : Ctl_parser_types.ast_node -> ALVar.alexp -> bool
 val has_visibility_attribute : Ctl_parser_types.ast_node -> ALVar.alexp -> bool
 
 val has_used_attribute : Ctl_parser_types.ast_node -> bool
+
+val within_available_class_block : CLintersContext.context -> Ctl_parser_types.ast_node -> bool

infer/src/clang/cTL.ml

@@ -800,6 +800,8 @@ let rec eval_Atomic _pred_name args an lcxt =
    -> CPredicates.has_visibility_attribute an vis
   | "has_used_attribute", [], an
    -> CPredicates.has_used_attribute an
+  | "within_available_class_block", [], an
+   -> CPredicates.within_available_class_block lcxt an
   | _
    -> failwith ("ERROR: Undefined Predicate or wrong set of arguments: '" ^ pred_name ^ "'")
 

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

@@ -4,9 +4,8 @@ codetoanalyze/objc/ioslints/unavailable_api_allowed_cases.m, Unavailable_api_all
 codetoanalyze/objc/ioslints/unavailable_api_allowed_cases.m, Unavailable_api_allowed_cases_with_responds_to_selector_in_else:, 71, UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK, []
 codetoanalyze/objc/ioslints/unavailable_api_allowed_cases.m, Unavailable_api_allowed_cases_without_instances_responds_to_selector, 95, UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK, []
 codetoanalyze/objc/ioslints/unavailable_api_allowed_cases.m, Unavailable_api_allowed_cases_without_responds_to_selector:, 64, UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK, []
-codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m, OpenURLOptionsFromSourceApplication, 51, UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK, []
+codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m, OpenURLOptionsFromSourceApplication, 68, UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK, []
 codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m, Unavailable_api_in_supported_ios_sdk_test:and:, 28, UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK, []
 codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m, Unavailable_api_in_supported_ios_sdk_unsupported_class, 34, UNAVAILABLE_CLASS_IN_SUPPORTED_IOS_SDK, []
-codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m, Unavailable_api_in_supported_ios_sdk_unsupported_class, 34, UNAVAILABLE_CLASS_IN_SUPPORTED_IOS_SDK, []
-codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m, Unavailable_api_in_supported_ios_sdk_unsupported_class_with_attributes:, 44, UNAVAILABLE_CLASS_IN_SUPPORTED_IOS_SDK, []
+codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m, Unavailable_api_in_supported_ios_sdk_unsupported_class_with_attributes:, 53, UNAVAILABLE_CLASS_IN_SUPPORTED_IOS_SDK, []
 codetoanalyze/objc/ioslints/unavailable_property_ios.m, FNFPlayerLayer_initWithConfigs:, 22, UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK, []

infer/tests/codetoanalyze/objc/ioslints/unavailable_api_in_supported_ios_sdk.m

@@ -38,11 +38,28 @@ NS_CLASS_AVAILABLE(10_12, 10_0)
     NSLog(@"");
   }
 }
+// no bug
+- (void)unsupported_class_with_check {
+  if ([AVPlayerLooper class]) {
+    AVPlayerLooper* looper =
+        [[AVPlayerLooper alloc] initWithPlayer:nil
+                                  templateItem:nil
+                                     timeRange:kCMTimeRangeInvalid];
+  }
+}
 
 // bug
 - (void)unsupported_class_with_attributes:(nonnull Unav_class*)c {
-  [c m];
+  [Unav_class new];
+}
+
+// no bug
+- (void)unsupported_class_with_attributes_with_check:(nonnull Unav_class*)c {
+  if ([Unav_class class]) {
+    [[Unav_class alloc] init];
+  }
 }
+
 @end
 
 static NSDictionary* OpenURLOptionsFromSourceApplication(