[racerd] fix NSObject.init treatment of ownership

Summary: NSObject.init has no summary yet isn't recognised as allocating memory. This breaks ownership tracking.

Reviewed By: jvillard

Differential Revision: D10852627

fbshipit-source-id: 95e016c84

infer/src/concurrency/RacerDModels.ml

@@ -201,9 +201,20 @@ let is_functional pname =
   is_annotated_functional pname || is_modeled_functional pname
 
 
+let nsobject = Typ.Name.Objc.from_qual_name (QualifiedCppName.of_qual_string "NSObject")
+
 let acquires_ownership pname tenv =
+  let is_nsobject_init = function
+    | Typ.Procname.ObjC_Cpp
+        {kind= Typ.Procname.ObjC_Cpp.ObjCInstanceMethod; method_name= "init"; class_name} ->
+        Typ.Name.equal class_name nsobject
+    | _ ->
+        false
+  in
   let is_allocation pn =
-    Typ.Procname.equal pn BuiltinDecl.__new || Typ.Procname.equal pn BuiltinDecl.__new_array
+    Typ.Procname.equal pn BuiltinDecl.__new
+    || Typ.Procname.equal pn BuiltinDecl.__new_array
+    || is_nsobject_init pn
   in
   (* identify library functions that maintain ownership invariants behind the scenes *)
   let is_owned_in_library = function

infer/tests/codetoanalyze/objcpp/racerd/Ctor.mm

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2018-present, Facebook, Inc.
+ *
+ * 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>
+#import <mutex>
+
+@interface Ctor : NSObject
+- (instancetype)init;
+- (void)write:(int)data;
+@end
+
+@implementation Ctor {
+  std::mutex _mutex;
+  int _data;
+}
+
+- (instancetype)init {
+  if (!(self = [super init])) {
+    return nil;
+  }
+
+  int i = _data;
+
+  return self;
+}
+
+- (void)write:(int)data {
+  _mutex.lock();
+  _data = data;
+  _mutex.unlock();
+}
+@end

infer/tests/codetoanalyze/objcpp/racerd/CtorInherit.mm

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2018-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+#import "Ctor.mm"
+#import <mutex>
+
+@interface CtorInherit : Ctor
+- (instancetype)init;
+- (void)writeZero;
+@end
+
+@implementation CtorInherit
+
+- (instancetype)init {
+  if (!(self = [super init])) {
+    return nil;
+  }
+  return self;
+}
+
+- (void)writeZero {
+  [self write:0];
+}
+@end