[threadsafety] Treat clone() as aquiring ownership

Reviewed By: sblackshear

Differential Revision: D4961331

fbshipit-source-id: 60a9a36

infer/src/checkers/ThreadSafety.ml

@@ -350,6 +350,9 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
             | ("java.lang.Class" | "java.lang.reflect.Constructor"), "newInstance" ->
                 (* reflection can perform allocations *)
                 true
+            | "java.lang.Object" , "clone" ->
+                (* cloning is like allocation *)
+                true
             | "java.lang.ThreadLocal", "get" ->
                 (* ThreadLocal prevents sharing between threads behind the scenes *)
                 true

infer/tests/codetoanalyze/java/threadsafety/Ownership.java

@@ -376,6 +376,15 @@ public class Ownership {
     c.f = new Object();
   }
 
+  void cloningAquiresOwnershipOk(){
+   Ownership ow;
+   try {
+     ow = (Ownership) this.clone();
+     ow.field = null;
+   }
+   catch (CloneNotSupportedException e) {}
+  }
+
 }