[AL] Adding predicate for AL rule to check that a variable of a specific type is being captured in a block

Reviewed By: ddino

Differential Revision: D17261362

fbshipit-source-id: 81f2e4bdb

infer/src/al/cPredicates.ml

@@ -1592,3 +1592,20 @@ let is_in_source_file an path_re =
 
 let is_referencing_decl_from_source_file an path_re =
   source_file_matches (Ctl_parser_types.get_referenced_decl_source_file an) path_re
+
+
+let captured_var_of_type typ captured_var =
+  match captured_var.Clang_ast_t.bcv_variable with
+  | Some dr ->
+      let _, _, qt = CAst_utils.get_info_from_decl_ref dr in
+      type_ptr_equal_type qt.Clang_ast_t.qt_type_ptr (ALVar.alexp_to_string typ)
+  | _ ->
+      false
+
+
+let objc_block_is_capturing_var_of_type an typ =
+  match an with
+  | Ctl_parser_types.Decl (Clang_ast_t.BlockDecl (_, bdi)) ->
+      List.exists ~f:(captured_var_of_type typ) bdi.bdi_captured_variables
+  | _ ->
+      false

infer/src/al/cPredicates.mli

@@ -14,6 +14,9 @@ type t = ALVar.formula_id * ALVar.alexp list [@@deriving compare]
 val captured_variables_cxx_ref : Ctl_parser_types.ast_node -> Clang_ast_t.named_decl_info list
 (** list of cxx references captured by an ObjC Block *)
 
+val objc_block_is_capturing_var_of_type : Ctl_parser_types.ast_node -> ALVar.t -> bool
+(** true if the ObjC Block captures a variable of a given type *)
+
 val objc_block_is_capturing_values : Ctl_parser_types.ast_node -> bool
 (** true if the ObjC Block captures any variables *)
 

infer/src/al/cTL.ml

@@ -1222,6 +1222,8 @@ let rec eval_Atomic pred_name_ args an lcxt =
       CPredicates.is_in_source_file an path_re
   | "is_referencing_decl_from_source_file", [path_re], an ->
       CPredicates.is_referencing_decl_from_source_file an path_re
+  | "objc_block_is_capturing_var_of_type", [typ], an ->
+      CPredicates.objc_block_is_capturing_var_of_type an typ
   | _ ->
       L.(die ExternalError) "Undefined Predicate or wrong set of arguments: '%s'" pred_name
 

infer/tests/codetoanalyze/objc/linters-for-test-only/al_definitions/linters_example.al

@@ -877,3 +877,14 @@ DEFINE-CHECKER TEST_IS_OPTIONAL_METHOD = {
   SET message = "This is an optional method";
 
 };
+
+DEFINE-CHECKER IVAR_CAPTURED_IN_OBJC_BLOCK = {
+		SET report_when =
+ 			WHEN
+				objc_block_is_capturing_var_of_type("Ivars*")
+ 			HOLDS-IN-NODE BlockDecl;
+
+	  SET message = "Found ivar of a given type captured in block";
+    SET severity = "ERROR";
+		SET mode = "ON";
+	};

infer/tests/codetoanalyze/objc/linters-for-test-only/issues.exp

@@ -329,6 +329,7 @@ codetoanalyze/objc/linters-for-test-only/unavailable.m, FooClass::new, 12, TEST_
 codetoanalyze/objc/linters-for-test-only/unavailable.m, FooClass::new, 12, TEST_IS_OVERRIDING_METHOD, no_bucket, WARNING, []
 codetoanalyze/objc/linters-for-test-only/unavailable.m, FooClass::new, 12, TEST_UNAVAILABLE_ATTR, no_bucket, WARNING, []
 codetoanalyze/objc/linters-for-test-only/unavailable.m, FooClass::newWithFoo, 13, TEST_INSTANCE_TYPE, no_bucket, WARNING, []
+codetoanalyze/objc/linters-for-test-only/variables_captured_in_block.m, objc_block, 26, IVAR_CAPTURED_IN_OBJC_BLOCK, no_bucket, ERROR, []
 codetoanalyze/objc/linters-for-test-only/visibility.c, bar, 29, TEST_DEFAULT_VISIBILITY, no_bucket, WARNING, []
 codetoanalyze/objc/linters-for-test-only/visibility.c, bar, 30, TEST_DEFAULT_VISIBILITY, no_bucket, WARNING, []
 codetoanalyze/objc/linters-for-test-only/visibility.c, bar, 31, TEST_HIDDEN_VISIBILITY, no_bucket, WARNING, []

infer/tests/codetoanalyze/objc/linters-for-test-only/variables_captured_in_block.m

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+#import <Foundation/NSObject.h>
+
+typedef struct LSIvarsContext {
+  void* ivars;
+} LSIvarsContext;
+
+typedef struct Ivars {
+  void (*dealloc)(struct Ivars*);
+  NSString* str;
+} Ivars;
+
+@interface T : NSObject
+@end
+@implementation T
+
+- (void)m {
+  LSIvarsContext __blablaContext;
+  Ivars* blabla = (Ivars*)__blablaContext.ivars;
+
+  dispatch_async(dispatch_get_global_queue(0, 0), ^{
+    blabla->str = @"str";
+  });
+}
+@end