Add the [JSpecify](http://jspecify.org) `@Nullable` to `equals(Object)` if it is available.

More exactly, we will generate `equals(@Nullable Object)` if we know a `@Nullable` annotation. We know a `@Nullable` annotation if one is mentioned in a method parameter or return type of the `@AutoValue` [etc] class; this was already true before this CL. What's new is that we also know a `@Nullable` annotation if one is available in the compilation environment and matches the one we expect. That in turn is `@org.jspecify.nullness.Nullable` by default, but can be overridden or suppressed with a new `-A` option.

We also insert `@Nullable` for `@AutoAnnotation` implementations, though currently we don't have logic to find one that might be referenced from methods.

RELNOTES=n/a
PiperOrigin-RevId: 375811563

15 files changed, 207 insertions, 20 deletions

diff --git a/value/src/it/functional/src/test/java/com/google/auto/value/AutoAnnotationTest.java b/value/src/it/functional/src/test/java/com/google/auto/value/AutoAnnotationTest.java
index 23c1f590..f894d6b9 100644
--- a/value/src/it/functional/src/test/java/com/google/auto/value/AutoAnnotationTest.java
+++ b/value/src/it/functional/src/test/java/com/google/auto/value/AutoAnnotationTest.java
@@ -16,10 +16,12 @@
 package com.google.auto.value;
 
 import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.TruthJUnit.assume;
 
 import com.google.auto.value.annotations.Empty;
 import com.google.auto.value.annotations.GwtArrays;
 import com.google.auto.value.annotations.StringValues;
+import com.google.common.base.StandardSystemProperty;
 import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
@@ -30,6 +32,7 @@ import java.io.ObjectStreamClass;
 import java.lang.annotation.Annotation;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -39,6 +42,7 @@ import java.util.List;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
+import org.junit.AssumptionViolatedException;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -67,6 +71,33 @@ public class AutoAnnotationTest {
   }
 
   @Test
+  public void testEqualsParameterAnnotation() throws ReflectiveOperationException {
+    assume()
+        .that(Double.parseDouble(StandardSystemProperty.JAVA_SPECIFICATION_VERSION.value()))
+        .isAtLeast(8.0);
+    Class<? extends Annotation> jspecifyNullable;
+    try {
+      jspecifyNullable =
+          Class.forName("org.jspecify.nullness.Nullable").asSubclass(Annotation.class);
+    } catch (ClassNotFoundException e) {
+      throw new AssumptionViolatedException("No JSpecify @Nullable available", e);
+    }
+    @SuppressWarnings("GetClassOnAnnotation") // yes, I really want the implementation class
+    Class<? extends StringValues> autoAnnotationImpl = newStringValues(new String[0]).getClass();
+    Method equals = autoAnnotationImpl.getDeclaredMethod("equals", Object.class);
+    // The remaining faffing around with reflection is there because we have a Google-internal test
+    // that runs this code with -source 7 -target 7. We're really just doing this:
+    //   assertThat(equals.getAnnotatedParameterTypes()[0].isAnnotationPresent(jspecifyNullable))
+    //      .isTrue();
+    Method getAnnotatedParameterTypes = Method.class.getMethod("getAnnotatedParameterTypes");
+    Object[] annotatedParameterTypes = (Object[]) getAnnotatedParameterTypes.invoke(equals);
+    Method isAnnotationPresent =
+        annotatedParameterTypes[0].getClass().getMethod("isAnnotationPresent", Class.class);
+    assertThat(isAnnotationPresent.invoke(annotatedParameterTypes[0], jspecifyNullable))
+        .isEqualTo(true);
+  }
+
+  @Test
   public void testArraysAreCloned() {
     String[] array = {"Jekyll"};
     StringValues stringValues = newStringValues(array);
diff --git a/value/src/it/functional/src/test/java/com/google/auto/value/AutoValueJava8Test.java b/value/src/it/functional/src/test/java/com/google/auto/value/AutoValueJava8Test.java
index 3beab5e4..11aa5c16 100644
--- a/value/src/it/functional/src/test/java/com/google/auto/value/AutoValueJava8Test.java
+++ b/value/src/it/functional/src/test/java/com/google/auto/value/AutoValueJava8Test.java
@@ -55,6 +55,7 @@ import javax.lang.model.element.TypeElement;
 import javax.lang.model.util.ElementFilter;
 import javax.tools.Diagnostic;
 import javax.tools.JavaFileObject;
+import org.junit.AssumptionViolatedException;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -551,6 +552,34 @@ public class AutoValueJava8Test {
     }
   }
 
+  @AutoValue
+  abstract static class NoNullableRef {
+    abstract String foo();
+
+    static NoNullableRef of(String foo) {
+      return new AutoValue_AutoValueJava8Test_NoNullableRef(foo);
+    }
+  }
+
+  // Tests that we generate equals(@org.jspecify.nullness.Nullable x) if that annotation is
+  // available and there is no other @Nullable type annotation mentioned in the @AutoValue class.
+  // If there *are* other @Nullable type annotations, other test methods here will check that they
+  // are used instead.
+  @Test
+  public void testDefaultToJSpecifyNullable() throws ReflectiveOperationException {
+    Class<? extends Annotation> jspecifyNullable;
+    try {
+      jspecifyNullable =
+          Class.forName("org.jspecify.nullness.Nullable").asSubclass(Annotation.class);
+    } catch (ClassNotFoundException e) {
+      throw new AssumptionViolatedException("No JSpecify @Nullable available", e);
+    }
+    Class<? extends NoNullableRef> autoValueImpl = NoNullableRef.of("foo").getClass();
+    Method equals = autoValueImpl.getDeclaredMethod("equals", Object.class);
+    assertThat(equals.getAnnotatedParameterTypes()[0].isAnnotationPresent(jspecifyNullable))
+        .isTrue();
+  }
+
   @Test
   public void testBuilderWithUnprefixedGetter() {
     assumeTrue(javacHandlesTypeAnnotationsCorrectly);
diff --git a/value/src/main/java/com/google/auto/value/processor/AutoAnnotationProcessor.java b/value/src/main/java/com/google/auto/value/processor/AutoAnnotationProcessor.java
index eb87287b..edfa41ce 100644
--- a/value/src/main/java/com/google/auto/value/processor/AutoAnnotationProcessor.java
+++ b/value/src/main/java/com/google/auto/value/processor/AutoAnnotationProcessor.java
@@ -27,6 +27,7 @@ import com.google.auto.common.SuperficialValidation;
 import com.google.auto.service.AutoService;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Throwables;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.hash.Hashing;
@@ -46,6 +47,7 @@ import javax.annotation.processing.Processor;
 import javax.annotation.processing.RoundEnvironment;
 import javax.annotation.processing.SupportedAnnotationTypes;
 import javax.lang.model.SourceVersion;
+import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.AnnotationValue;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ElementKind;
@@ -79,11 +81,30 @@ import net.ltgt.gradle.incap.IncrementalAnnotationProcessorType;
 public class AutoAnnotationProcessor extends AbstractProcessor {
   public AutoAnnotationProcessor() {}
 
+  private Elements elementUtils;
+  private Types typeUtils;
+  private Nullables nullables;
+  private TypeMirror javaLangObject;
+
   @Override
   public SourceVersion getSupportedSourceVersion() {
     return SourceVersion.latestSupported();
   }
 
+  @Override
+  public ImmutableSet<String> getSupportedOptions() {
+    return ImmutableSet.of(Nullables.NULLABLE_OPTION);
+  }
+
+  @Override
+  public synchronized void init(ProcessingEnvironment processingEnv) {
+    super.init(processingEnv);
+    this.elementUtils = processingEnv.getElementUtils();
+    this.typeUtils = processingEnv.getTypeUtils();
+    this.nullables = new Nullables(processingEnv);
+    this.javaLangObject = elementUtils.getTypeElement("java.lang.Object").asType();
+  }
+
   /**
    * Issue a compilation error. This method does not throw an exception, since we want to continue
    * processing and perhaps report other errors.
@@ -104,13 +125,8 @@ public class AutoAnnotationProcessor extends AbstractProcessor {
     return new AbortProcessingException();
   }
 
-  private Elements elementUtils;
-  private Types typeUtils;
-
   @Override
   public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
-    elementUtils = processingEnv.getElementUtils();
-    typeUtils = processingEnv.getTypeUtils();
     process(roundEnv);
     return false;
   }
@@ -163,6 +179,7 @@ public class AutoAnnotationProcessor extends AbstractProcessor {
     vars.generated = getGeneratedTypeName();
     vars.members = members;
     vars.params = parameters;
+    vars.equalsParameterType = equalsParameterType();
     vars.pkg = pkg;
     vars.wrapperTypesUsedInCollections = wrapperTypesUsedInCollections;
     vars.gwtCompatible = isGwtCompatible(annotationElement);
@@ -186,6 +203,18 @@ public class AutoAnnotationProcessor extends AbstractProcessor {
         .orElse("");
   }
 
+  private String equalsParameterType() {
+    // Unlike AutoValue, we don't currently try to guess a @Nullable based on the methods in your
+    // class. It's the default one or nothing.
+    ImmutableList<AnnotationMirror> equalsParameterAnnotations =
+        nullables
+            .appropriateNullableGivenMethods(ImmutableSet.of())
+            .map(ImmutableList::of)
+            .orElse(ImmutableList.of());
+    return TypeEncoder.encodeWithAnnotations(
+        javaLangObject, equalsParameterAnnotations, ImmutableSet.of());
+  }
+
   /**
    * Returns the hashCode of the given AnnotationValue, if that hashCode is guaranteed to be always
    * the same. The hashCode of a String or primitive type never changes. The hashCode of a Class or
diff --git a/value/src/main/java/com/google/auto/value/processor/AutoAnnotationTemplateVars.java b/value/src/main/java/com/google/auto/value/processor/AutoAnnotationTemplateVars.java
index dc39e06b..11bc896c 100644
--- a/value/src/main/java/com/google/auto/value/processor/AutoAnnotationTemplateVars.java
+++ b/value/src/main/java/com/google/auto/value/processor/AutoAnnotationTemplateVars.java
@@ -35,6 +35,12 @@ class AutoAnnotationTemplateVars extends TemplateVars {
    */
   Map<String, AutoAnnotationProcessor.Parameter> params;
 
+  /**
+   * A string representing the parameter type declaration of the equals(Object) method, including
+   * any annotations.
+   */
+  String equalsParameterType;
+
   /** The encoded form of the {@code Generated} class, or empty if it is not available. */
   String generated;
 
diff --git a/value/src/main/java/com/google/auto/value/processor/AutoOneOfProcessor.java b/value/src/main/java/com/google/auto/value/processor/AutoOneOfProcessor.java
index b48d2ea4..a1daebba 100644
--- a/value/src/main/java/com/google/auto/value/processor/AutoOneOfProcessor.java
+++ b/value/src/main/java/com/google/auto/value/processor/AutoOneOfProcessor.java
@@ -69,6 +69,11 @@ public class AutoOneOfProcessor extends AutoValueishProcessor {
   }
 
   @Override
+  public ImmutableSet<String> getSupportedOptions() {
+    return ImmutableSet.of(Nullables.NULLABLE_OPTION);
+  }
+
+  @Override
   void processType(TypeElement autoOneOfType) {
     if (autoOneOfType.getKind() != ElementKind.CLASS) {
       errorReporter()
diff --git a/value/src/main/java/com/google/auto/value/processor/AutoValueProcessor.java b/value/src/main/java/com/google/auto/value/processor/AutoValueProcessor.java
index ef1f3098..acc01981 100644
--- a/value/src/main/java/com/google/auto/value/processor/AutoValueProcessor.java
+++ b/value/src/main/java/com/google/auto/value/processor/AutoValueProcessor.java
@@ -131,14 +131,17 @@ public class AutoValueProcessor extends AutoValueishProcessor {
   }
 
   @Override
-  public Set<String> getSupportedOptions() {
+  public ImmutableSet<String> getSupportedOptions() {
     ImmutableSet.Builder<String> builder = ImmutableSet.builder();
     AutoValueExtension.IncrementalExtensionType incrementalType =
         extensions.stream()
             .map(e -> e.incrementalType(processingEnv))
             .min(naturalOrder())
             .orElse(AutoValueExtension.IncrementalExtensionType.ISOLATING);
-    builder.add(OMIT_IDENTIFIERS_OPTION).addAll(optionsFor(incrementalType));
+    builder
+        .add(OMIT_IDENTIFIERS_OPTION)
+        .add(Nullables.NULLABLE_OPTION)
+        .addAll(optionsFor(incrementalType));
     for (AutoValueExtension extension : extensions) {
       builder.addAll(extension.getSupportedOptions());
     }
diff --git a/value/src/main/java/com/google/auto/value/processor/AutoValueishProcessor.java b/value/src/main/java/com/google/auto/value/processor/AutoValueishProcessor.java
index a494b9a6..203a5ea5 100644
--- a/value/src/main/java/com/google/auto/value/processor/AutoValueishProcessor.java
+++ b/value/src/main/java/com/google/auto/value/processor/AutoValueishProcessor.java
@@ -109,11 +109,13 @@ abstract class AutoValueishProcessor extends AbstractProcessor {
   private String simpleAnnotationName;
 
   private ErrorReporter errorReporter;
+  private Nullables nullables;
 
   @Override
   public synchronized void init(ProcessingEnvironment processingEnv) {
     super.init(processingEnv);
     errorReporter = new ErrorReporter(processingEnv);
+    nullables = new Nullables(processingEnv);
   }
 
   final ErrorReporter errorReporter() {
@@ -461,7 +463,7 @@ abstract class AutoValueishProcessor extends AbstractProcessor {
     vars.toString = methodsToGenerate.containsKey(ObjectMethod.TO_STRING);
     vars.equals = methodsToGenerate.containsKey(ObjectMethod.EQUALS);
     vars.hashCode = methodsToGenerate.containsKey(ObjectMethod.HASH_CODE);
-    Optional<AnnotationMirror> nullable = Nullables.nullableMentionedInMethods(methods);
+    Optional<AnnotationMirror> nullable = nullables.appropriateNullableGivenMethods(methods);
     vars.equalsParameterType = equalsParameterType(methodsToGenerate, nullable);
     vars.serialVersionUID = getSerialVersionUID(type);
   }
diff --git a/value/src/main/java/com/google/auto/value/processor/Nullables.java b/value/src/main/java/com/google/auto/value/processor/Nullables.java
index 3df23222..bcb3ca0a 100644
--- a/value/src/main/java/com/google/auto/value/processor/Nullables.java
+++ b/value/src/main/java/com/google/auto/value/processor/Nullables.java
@@ -17,13 +17,20 @@ package com.google.auto.value.processor;
 
 import static java.util.stream.Collectors.toList;
 
+import com.google.auto.common.MoreTypes;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Stream;
+import javax.annotation.processing.ProcessingEnvironment;
+import javax.lang.model.SourceVersion;
 import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.AnnotationValue;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.type.ArrayType;
@@ -36,9 +43,49 @@ import javax.lang.model.util.SimpleTypeVisitor8;
 
 class Nullables {
   /**
+   * If set to a non-empty string, defines which {@code @Nullable} type annotation should be used by
+   * default. If set to an empty string, does not insert {@code @Nullable} unless it is referenced
+   * in the {@code @AutoValue} methods. If unset, defaults to {@value #DEFAULT_NULLABLE}.
+   */
+  static final String NULLABLE_OPTION = "com.google.auto.value.NullableTypeAnnotation";
+
+  private static final String DEFAULT_NULLABLE = "org.jspecify.nullness.Nullable";
+
+  private final Optional<AnnotationMirror> defaultNullable;
+
+  Nullables(ProcessingEnvironment processingEnv) {
+    // -Afoo without `=` sets "foo" to null in the getOptions() map.
+    String nullableOption =
+        Strings.nullToEmpty(
+            processingEnv.getOptions().getOrDefault(NULLABLE_OPTION, DEFAULT_NULLABLE));
+    this.defaultNullable =
+        (!nullableOption.isEmpty()
+                && processingEnv.getSourceVersion().ordinal() >= SourceVersion.RELEASE_8.ordinal())
+            ? Optional.ofNullable(processingEnv.getElementUtils().getTypeElement(nullableOption))
+                .map(t -> annotationMirrorOf(MoreTypes.asDeclared(t.asType())))
+            : Optional.empty();
+  }
+
+  private static AnnotationMirror annotationMirrorOf(DeclaredType annotationType) {
+    return new AnnotationMirror() {
+      @Override
+      public DeclaredType getAnnotationType() {
+        return annotationType;
+      }
+
+      @Override
+      public ImmutableMap<? extends ExecutableElement, ? extends AnnotationValue>
+          getElementValues() {
+        return ImmutableMap.of();
+      }
+    };
+  }
+
+  /**
    * Returns the type of a {@code @Nullable} type-annotation, if one is found anywhere in the
    * signatures of the given methods.
    */
+  @VisibleForTesting
   static Optional<AnnotationMirror> nullableMentionedInMethods(
       Collection<ExecutableElement> methods) {
     return methods.stream()
@@ -53,6 +100,19 @@ class Nullables {
         .orElse(Optional.empty());
   }
 
+  /**
+   * Returns the type of an appropriate {@code @Nullable} type-annotation, given a set of methods
+   * that are known to be in the same compilation as the code being generated. If one of those
+   * methods contains an appropriate {@code @Nullable} annotation on a parameter or return type,
+   * this method will return that. Otherwise, if the <a href="http://jspecify.org">JSpecify</a>
+   * {@code @Nullable} is available, this method will return it. Otherwise, this method will return
+   * an empty {@code Optional}.
+   */
+  Optional<AnnotationMirror> appropriateNullableGivenMethods(
+      Collection<ExecutableElement> methods) {
+    return nullableMentionedInMethods(methods).map(Optional::of).orElse(defaultNullable);
+  }
+
   private static Optional<AnnotationMirror> nullableIn(TypeMirror type) {
     return new NullableFinder().visit(type);
   }
@@ -61,7 +121,7 @@ class Nullables {
       List<? extends AnnotationMirror> annotations) {
     return annotations.stream()
         .filter(a -> a.getAnnotationType().asElement().getSimpleName().contentEquals("Nullable"))
-        .map(a -> (AnnotationMirror) a)  // get rid of the pesky wildcard
+        .map(a -> (AnnotationMirror) a) // get rid of the pesky wildcard
         .findFirst();
   }
 
@@ -128,6 +188,4 @@ class Nullables {
           .orElse(Optional.empty());
     }
   }
-
-  private Nullables() {}
 }
diff --git a/value/src/main/java/com/google/auto/value/processor/autoannotation.vm b/value/src/main/java/com/google/auto/value/processor/autoannotation.vm
index 590992ee..5cdad629 100644
--- a/value/src/main/java/com/google/auto/value/processor/autoannotation.vm
+++ b/value/src/main/java/com/google/auto/value/processor/autoannotation.vm
@@ -213,7 +213,7 @@ final class $className implements $annotationName, `java.io.Serializable` {
 #end
 
   @`java.lang.Override`
-  public boolean equals(Object o) {
+  public boolean equals($equalsParameterType o) {
     if (o == this) {
       return true;
     }
diff --git a/value/src/test/java/com/google/auto/value/processor/AutoAnnotationCompilationTest.java b/value/src/test/java/com/google/auto/value/processor/AutoAnnotationCompilationTest.java
index f8070245..0227d746 100644
--- a/value/src/test/java/com/google/auto/value/processor/AutoAnnotationCompilationTest.java
+++ b/value/src/test/java/com/google/auto/value/processor/AutoAnnotationCompilationTest.java
@@ -131,6 +131,7 @@ public class AutoAnnotationCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoAnnotationProcessor())
+            .withOptions("-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(annotationFactoryJavaFile, myAnnotationJavaFile, myEnumJavaFile);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
@@ -195,6 +196,7 @@ public class AutoAnnotationCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoAnnotationProcessor())
+            .withOptions("-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(annotationFactoryJavaFile, myAnnotationJavaFile);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
@@ -294,6 +296,7 @@ public class AutoAnnotationCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoAnnotationProcessor())
+            .withOptions("-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(annotationFactoryJavaFile, myAnnotationJavaFile, gwtCompatibleJavaFile);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
@@ -434,6 +437,7 @@ public class AutoAnnotationCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoAnnotationProcessor())
+            .withOptions("-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(annotationFactoryJavaFile, myEnumJavaFile, myAnnotationJavaFile);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
diff --git a/value/src/test/java/com/google/auto/value/processor/AutoOneOfCompilationTest.java b/value/src/test/java/com/google/auto/value/processor/AutoOneOfCompilationTest.java
index 2ae98b7e..788b543a 100644
--- a/value/src/test/java/com/google/auto/value/processor/AutoOneOfCompilationTest.java
+++ b/value/src/test/java/com/google/auto/value/processor/AutoOneOfCompilationTest.java
@@ -237,7 +237,8 @@ public class AutoOneOfCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoOneOfProcessor())
-            .withOptions("-Xlint:-processing", "-implicit:none")
+            .withOptions(
+                "-Xlint:-processing", "-implicit:none", "-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(javaFileObject);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
@@ -321,7 +322,8 @@ public class AutoOneOfCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoOneOfProcessor())
-            .withOptions("-Xlint:-processing", "-implicit:none")
+            .withOptions(
+                "-Xlint:-processing", "-implicit:none", "-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(javaFileObject);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
diff --git a/value/src/test/java/com/google/auto/value/processor/AutoValueCompilationTest.java b/value/src/test/java/com/google/auto/value/processor/AutoValueCompilationTest.java
index 1baf4b4d..afb86ec1 100644
--- a/value/src/test/java/com/google/auto/value/processor/AutoValueCompilationTest.java
+++ b/value/src/test/java/com/google/auto/value/processor/AutoValueCompilationTest.java
@@ -118,7 +118,10 @@ public class AutoValueCompilationTest {
             "  }",
             "}");
     Compilation compilation =
-        javac().withProcessors(new AutoValueProcessor()).compile(javaFileObject);
+        javac()
+            .withProcessors(new AutoValueProcessor())
+            .withOptions("-A" + Nullables.NULLABLE_OPTION + "=")
+            .compile(javaFileObject);
     assertThat(compilation)
         .generatedSourceFile("foo.bar.AutoValue_Baz")
         .hasSourceEquivalentTo(expectedOutput);
@@ -216,7 +219,10 @@ public class AutoValueCompilationTest {
             "  }",
             "}");
     Compilation compilation =
-        javac().withProcessors(new AutoValueProcessor()).compile(javaFileObject);
+        javac()
+            .withProcessors(new AutoValueProcessor())
+            .withOptions("-A" + Nullables.NULLABLE_OPTION + "=")
+            .compile(javaFileObject);
     assertThat(compilation)
         .generatedSourceFile("foo.bar.AutoValue_Baz")
         .hasSourceEquivalentTo(expectedOutput);
@@ -347,7 +353,8 @@ public class AutoValueCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoValueProcessor())
-            .withOptions("-Xlint:-processing", "-implicit:none")
+            .withOptions(
+                "-Xlint:-processing", "-implicit:none", "-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(annotFileObject, outerFileObject, nestyFileObject);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
@@ -1340,7 +1347,8 @@ public class AutoValueCompilationTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoValueProcessor())
-            .withOptions("-Xlint:-processing", "-implicit:none")
+            .withOptions(
+                "-Xlint:-processing", "-implicit:none", "-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(javaFileObject, nestedJavaFileObject);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
diff --git a/value/src/test/java/com/google/auto/value/processor/ExtensionTest.java b/value/src/test/java/com/google/auto/value/processor/ExtensionTest.java
index 8f74d5df..d41fb145 100644
--- a/value/src/test/java/com/google/auto/value/processor/ExtensionTest.java
+++ b/value/src/test/java/com/google/auto/value/processor/ExtensionTest.java
@@ -172,6 +172,7 @@ public class ExtensionTest {
     Compilation compilation =
         javac()
             .withProcessors(new AutoValueProcessor(ImmutableList.of(new FooExtension())))
+            .withOptions("-A" + Nullables.NULLABLE_OPTION + "=")
             .compile(javaFileObject);
     assertThat(compilation).succeededWithoutWarnings();
     assertThat(compilation)
diff --git a/value/src/test/java/com/google/auto/value/processor/GeneratedDoesNotExistTest.java b/value/src/test/java/com/google/auto/value/processor/GeneratedDoesNotExistTest.java
index f3d3d611..2e33ddff 100644
--- a/value/src/test/java/com/google/auto/value/processor/GeneratedDoesNotExistTest.java
+++ b/value/src/test/java/com/google/auto/value/processor/GeneratedDoesNotExistTest.java
@@ -48,6 +48,8 @@ import org.junit.runners.Parameterized.Parameters;
  */
 @RunWith(Parameterized.class)
 public class GeneratedDoesNotExistTest {
+  private static final ImmutableList<String> STANDARD_OPTIONS =
+      ImmutableList.of("-A" + Nullables.NULLABLE_OPTION + "=");
 
   @Parameters(name = "{0}")
   public static Collection<Object[]> data() {
@@ -57,12 +59,16 @@ public class GeneratedDoesNotExistTest {
       // TODO(b/72513371): use --release 8 once compile-testing supports that
       params.add(
           new Object[] {
-            ImmutableList.of(), "javax.annotation.processing.Generated",
+            STANDARD_OPTIONS, "javax.annotation.processing.Generated",
           });
     }
     params.add(
         new Object[] {
-          ImmutableList.of("-source", "8", "-target", "8"), "javax.annotation.Generated",
+          ImmutableList.<String>builder()
+              .addAll(STANDARD_OPTIONS)
+              .add("-source", "8", "-target", "8")
+              .build(),
+          "javax.annotation.Generated",
         });
     return params.build();
   }
diff --git a/value/src/test/java/com/google/auto/value/processor/PropertyAnnotationsTest.java b/value/src/test/java/com/google/auto/value/processor/PropertyAnnotationsTest.java
index 2c3bea0d..0ada36bb 100644
--- a/value/src/test/java/com/google/auto/value/processor/PropertyAnnotationsTest.java
+++ b/value/src/test/java/com/google/auto/value/processor/PropertyAnnotationsTest.java
@@ -274,6 +274,7 @@ public class PropertyAnnotationsTest {
 
     assertAbout(javaSource())
         .that(javaFileObject)
+        .withCompilerOptions("-A" + Nullables.NULLABLE_OPTION + "=")
         .processedWith(new AutoValueProcessor())
         .compilesWithoutError()
         .and()
@@ -514,6 +515,7 @@ public class PropertyAnnotationsTest {
 
     assertAbout(javaSource())
         .that(inputFile)
+        .withCompilerOptions("-A" + Nullables.NULLABLE_OPTION + "=")
         .processedWith(new AutoValueProcessor())
         .compilesWithoutError()
         .and()
@@ -552,6 +554,7 @@ public class PropertyAnnotationsTest {
 
     assertAbout(javaSource())
         .that(inputFile)
+        .withCompilerOptions("-A" + Nullables.NULLABLE_OPTION + "=")
         .processedWith(new AutoValueProcessor())
         .compilesWithoutError()
         .and()