[thread-safety] assume findViewById returns ownership

Reviewed By: jaegs

Differential Revision: D4901258

fbshipit-source-id: a4c4dab

infer/src/checkers/ThreadSafety.ml

@@ -296,6 +296,9 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
             | "java.lang.ThreadLocal", "get" ->
                 (* ThreadLocal prevents sharing between threads behind the scenes *)
                 true
+            | ("android.app.Activity" | "android.view.View"), "findViewById" ->
+                (* assume findViewById creates fresh View's (note: not always true) *)
+                true
             | "android.support.v4.util.Pools$SynchronizedPool", "acquire" ->
                 (* a pool should own all of its objects *)
                 true

infer/tests/codetoanalyze/java/threadsafety/AndroidModels.java

@@ -11,11 +11,18 @@ package codetoanalyze.java.checkers;
 
 import javax.annotation.concurrent.ThreadSafe;
 
+import android.app.Activity;
+import android.content.Context;
 import android.content.res.AssetManager;
 import android.content.res.Configuration;
 import android.content.res.Resources;
+import android.view.View;
 import android.util.DisplayMetrics;
 
+class MyActivity extends Activity {
+
+}
+
 class MyResources extends Resources {
 
   public MyResources(AssetManager assets, DisplayMetrics metrics, Configuration config) {
@@ -24,6 +31,16 @@ class MyResources extends Resources {
 
 }
 
+class MyView extends View {
+
+  boolean mField;
+
+  public MyView(Context c) {
+    super(c);
+  }
+
+}
+
 @ThreadSafe
 public class AndroidModels {
 
@@ -48,4 +65,14 @@ public class AndroidModels {
     mField = mResources.getConfiguration();
   }
 
+  public void findViewByIdOk1(MyView view) {
+    MyView subview = (MyView) view.findViewById(-1);
+    subview.mField = true; // ok;
+  }
+
+  public void findViewByIdOk2(MyActivity activity) {
+    MyView view = (MyView) activity.findViewById(-1);
+    view.mField = true; // ok;
+  }
+
 }