[Eradicate] Fix issue in Eradicate's check for field initialization

Summary:
Eradicate currently considers a field initialized if it's simply accessed (not written to),
or initialized with another initialized field.
This fixes the issue.

Reviewed By: jvillard

Differential Revision: D4449541

fbshipit-source-id: 06265a8

infer/src/eradicate/eradicateChecks.ml

@@ -259,10 +259,20 @@ let check_constructor_initialization tenv
                   list in
 
               let may_be_assigned_in_final_typestate =
+                let origin_is_initialized = function
+                  | TypeOrigin.Undef ->
+                      false
+                  | TypeOrigin.Field (f, _) ->
+                      (* field initialized with another field needing initialization *)
+                      let circular =
+                        IList.exists (fun (f', _, _) -> Ident.equal_fieldname f f') fields in
+                      not circular
+                  | _ ->
+                      true in
                 final_type_annotation_with
                   false
                   (Lazy.force final_initializer_typestates)
-                  (fun ta -> TypeAnnotation.get_origin ta <> TypeOrigin.Undef) in
+                  (fun ta -> origin_is_initialized (TypeAnnotation.get_origin ta)) in
 
               let may_be_nullable_in_final_typestate () =
                 final_type_annotation_with

infer/tests/codetoanalyze/java/eradicate/FieldNotInitialized.java

@@ -44,4 +44,56 @@ public class FieldNotInitialized {
     f = null; // OK  the framework could write null into the field
     g = null; // OK  the framework could write null into the field
   }
+
+
+  class OnlyRead {
+    Object o;
+
+    OnlyRead() {
+      Object x = o; // not initialized
+    }
+  }
+
+  class WriteItself {
+    Object o;
+
+    WriteItself() {
+      o = o; // not initialized
+    }
+  }
+
+  class Swap {
+    Object o1;
+    Object o2;
+
+    Swap() {
+      o1 = o2; // not initialized
+      o2 = new Object();
+    }
+  }
+
+  class SwapOK {
+    Object o1;
+    Object o2;
+
+    SwapOK() {
+      o1 = new Object();
+      o2 = o1;
+    }
+  }
+
+
+  class OnlyReadIndirect {
+    Object o1;
+    Object o2;
+
+    private void indirect() {
+      Object x = o1; // not initialized
+      o2 = new Object();
+    }
+
+    OnlyReadIndirect() {
+      indirect();
+    }
+  }
 }

infer/tests/codetoanalyze/java/eradicate/issues.exp

@@ -1,4 +1,8 @@
 codetoanalyze/java/eradicate/ActivityFieldNotInitialized.java, ActivityFieldNotInitialized$BadActivityWithOnCreate.<init>(ActivityFieldNotInitialized), 0, ERADICATE_FIELD_NOT_INITIALIZED, [Field `ActivityFieldNotInitialized$BadActivityWithOnCreate.field` is not initialized in the constructor and is not declared `@Nullable`]
+codetoanalyze/java/eradicate/FieldNotInitialized.java, FieldNotInitialized$OnlyRead.<init>(FieldNotInitialized), 0, ERADICATE_FIELD_NOT_INITIALIZED, [Field `FieldNotInitialized$OnlyRead.o` is not initialized in the constructor and is not declared `@Nullable`]
+codetoanalyze/java/eradicate/FieldNotInitialized.java, FieldNotInitialized$OnlyReadIndirect.<init>(FieldNotInitialized), 0, ERADICATE_FIELD_NOT_INITIALIZED, [Field `FieldNotInitialized$OnlyReadIndirect.o1` is not initialized in the constructor and is not declared `@Nullable`]
+codetoanalyze/java/eradicate/FieldNotInitialized.java, FieldNotInitialized$Swap.<init>(FieldNotInitialized), 0, ERADICATE_FIELD_NOT_INITIALIZED, [Field `FieldNotInitialized$Swap.o1` is not initialized in the constructor and is not declared `@Nullable`]
+codetoanalyze/java/eradicate/FieldNotInitialized.java, FieldNotInitialized$WriteItself.<init>(FieldNotInitialized), 0, ERADICATE_FIELD_NOT_INITIALIZED, [Field `FieldNotInitialized$WriteItself.o` is not initialized in the constructor and is not declared `@Nullable`]
 codetoanalyze/java/eradicate/FieldNotInitialized.java, FieldNotInitialized.<init>(), 0, ERADICATE_FIELD_NOT_INITIALIZED, [Field `FieldNotInitialized.a` is not initialized in the constructor and is not declared `@Nullable`]
 codetoanalyze/java/eradicate/FieldNotNullable.java, FieldNotNullable.<init>(Integer), -25, ERADICATE_FIELD_NOT_NULLABLE, [origin,Field `FieldNotNullable.static_s` can be null but is not declared `@Nullable`. (Origin: null constant at line 39)]
 codetoanalyze/java/eradicate/FieldNotNullable.java, FieldNotNullable.<init>(String), -2, ERADICATE_FIELD_NOT_NULLABLE, [origin,Field `FieldNotNullable.static_s` can be null but is not declared `@Nullable`. (Origin: null constant at line 39)]