[eradicate] no longer report Field Not Nullable warnings on the Fragment onDestroy method

Summary: It is common on Android code to recycle the `View` object by nullifying them in the `onDestroy()` or `onDestroyView()` methods. In this case, the outer `Fragment` object structure is preserve while the inner `View` object are set to null for the garbage collect to release the memory. However, if the fields are only set to `null` in the `onDestroy*()` methods, those fields cannot be `null` during the active lifecycle of the `Fragment`, so it is not necessary to annotate those fields with `Nullable`.

Reviewed By: mbouaziz

Differential Revision: D10024458

fbshipit-source-id: b05e538d9

infer/src/eradicate/eradicateChecks.ml

@@ -184,7 +184,8 @@ let check_field_assignment tenv find_canonical_duplicate curr_pdesc node instr_r
       | _ ->
           false
     in
-    (not (TypeAnnotation.get_value AnnotatedSignature.Nullable ta_lhs))
+    (not (AndroidFramework.is_destroy_method curr_pname))
+    && (not (TypeAnnotation.get_value AnnotatedSignature.Nullable ta_lhs))
     && TypeAnnotation.get_value AnnotatedSignature.Nullable ta_rhs
     && PatternMatch.type_is_class t_lhs
     && (not (Typ.Fieldname.Java.is_outer_instance fname))

infer/tests/codetoanalyze/java/eradicate/FieldNotNullable.java

@@ -7,15 +7,17 @@
 
 package codetoanalyze.java.eradicate;
 
+import android.app.Activity;
+import android.os.Bundle;
+import android.support.v4.app.Fragment;
+import android.view.View;
+
 import com.facebook.infer.annotation.Assertions;
 import com.facebook.infer.annotation.Initializer;
 import com.facebook.infer.annotation.SuppressFieldNotInitialized;
 
 import javax.annotation.Nullable;
 
-import android.app.Activity;
-import android.os.Bundle;
-
 abstract class A {
   final String fld;
 
@@ -27,6 +29,16 @@ abstract class A {
 // for butterknife
 @interface InjectView {}
 
+class FragmentExample extends Fragment {
+
+  View view;
+
+  @Override
+  public void onDestroyView() {
+    view = null;
+  }
+}
+
 public class FieldNotNullable extends A {
   @Nullable
   String x;

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

@@ -16,17 +16,18 @@ codetoanalyze/java/eradicate/FieldNotInitialized.java, codetoanalyze.java.eradic
 codetoanalyze/java/eradicate/FieldNotInitialized.java, codetoanalyze.java.eradicate.FieldNotInitialized$Swap.<init>(codetoanalyze.java.eradicate.FieldNotInitialized), 0, ERADICATE_FIELD_NOT_INITIALIZED, no_bucket, WARNING, [Field `FieldNotInitialized$Swap.o1` is not initialized in the constructor and is not declared `@Nullable`]
 codetoanalyze/java/eradicate/FieldNotInitialized.java, codetoanalyze.java.eradicate.FieldNotInitialized$WriteItself.<init>(codetoanalyze.java.eradicate.FieldNotInitialized), 0, ERADICATE_FIELD_NOT_INITIALIZED, no_bucket, WARNING, [Field `FieldNotInitialized$WriteItself.o` is not initialized in the constructor and is not declared `@Nullable`]
 codetoanalyze/java/eradicate/FieldNotInitialized.java, codetoanalyze.java.eradicate.FieldNotInitialized.<init>(), 0, ERADICATE_FIELD_NOT_INITIALIZED, no_bucket, WARNING, [Field `FieldNotInitialized.a` is not initialized in the constructor and is not declared `@Nullable`]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FieldNotNullable.<init>(java.lang.Integer), -25, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `FieldNotNullable.static_s` can be null but is not declared `@Nullable`. (Origin: null constant at line 35)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FieldNotNullable.<init>(java.lang.Integer), -25, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `FieldNotNullable.static_s` can be null but is not declared `@Nullable`. (Origin: null constant at line 47)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FieldNotNullable.<init>(java.lang.String), -2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `FieldNotNullable.static_s` can be null but is not declared `@Nullable`. (Origin: null constant at line 35)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FieldNotNullable.<init>(java.lang.String), -2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `FieldNotNullable.static_s` can be null but is not declared `@Nullable`. (Origin: null constant at line 47)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FieldNotNullable.setYNull():void, 1, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `FieldNotNullable.y` can be null but is not declared `@Nullable`. (Origin: null constant at line 53)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FieldNotNullable.setYNull():void, 1, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `FieldNotNullable.y` can be null but is not declared `@Nullable`. (Origin: null constant at line 65)]
 codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FieldNotNullable.setYNullable(java.lang.String):void, 1, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [Field `FieldNotNullable.y` can be null but is not declared `@Nullable`. (Origin: method parameter s)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.FlatBAD1(codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent):void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 249)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.FragmentExample.<init>(), 0, ERADICATE_FIELD_NOT_INITIALIZED, no_bucket, WARNING, [Field `FragmentExample.view` is not initialized in the constructor and is not declared `@Nullable`]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.FlatBAD2(codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent):void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 255)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.FlatBAD1(codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent):void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 261)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.NestedBAD1():void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 273)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.FlatBAD2(codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent):void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 267)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.NestedBAD2():void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 279)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.NestedBAD1():void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 285)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.NestedBAD3():void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 285)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.NestedBAD2():void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 291)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestPut.putNull(java.util.Map,java.lang.String):void, 2, ERADICATE_PARAMETER_NOT_NULLABLE, no_bucket, WARNING, [origin,`Map.put(...)` needs a non-null value in parameter 2 but argument `null` can be null. (Origin: null constant at line 323)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestFunctionsIdempotent.NestedBAD3():void, 2, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestFunctionsIdempotent.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: call to getS(...) at line 297)]
-codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestPut.putNull(java.util.Map,java.lang.String):void, 3, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestPut.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: null constant at line 323)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestPut.putNull(java.util.Map,java.lang.String):void, 2, ERADICATE_PARAMETER_NOT_NULLABLE, no_bucket, WARNING, [origin,`Map.put(...)` needs a non-null value in parameter 2 but argument `null` can be null. (Origin: null constant at line 335)]
+codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.NestedFieldAccess$TestPut.putNull(java.util.Map,java.lang.String):void, 3, ERADICATE_FIELD_NOT_NULLABLE, no_bucket, WARNING, [origin,Field `NestedFieldAccess$TestPut.dontAssignNull` can be null but is not declared `@Nullable`. (Origin: null constant at line 335)]
 codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.TestInitializerBuilder.build():codetoanalyze.java.eradicate.TestInitializer, 2, ERADICATE_CONDITION_REDUNDANT, no_bucket, WARNING, [The condition TestInitializerBuilder.required1 is always true according to the existing annotations.]
 codetoanalyze/java/eradicate/FieldNotNullable.java, codetoanalyze.java.eradicate.TestInitializerBuilder.build():codetoanalyze.java.eradicate.TestInitializer, 2, ERADICATE_CONDITION_REDUNDANT, no_bucket, WARNING, [The condition TestInitializerBuilder.required2 is always true according to the existing annotations.]
 codetoanalyze/java/eradicate/InconsistentSubclassAnnotation.java, codetoanalyze.java.eradicate.ExtendsExternalLibrary.externalMethod2(java.lang.Object):void, 0, ERADICATE_INCONSISTENT_SUBCLASS_PARAMETER_ANNOTATION, no_bucket, WARNING, [First parameter `object` of method `ExtendsExternalLibrary.externalMethod2(...)` is not `@Nullable` but is declared `@Nullable`in the parent class method `SomeExternalClass.externalMethod2(...)`.]