Make AutoValue processors generate valid code if @Generated is not available.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=170487026

7 files changed, 27 insertions, 6 deletions

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 4990a605..4a7780db 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
@@ -171,7 +171,7 @@ public class AutoAnnotationProcessor extends AbstractProcessor {
     vars.annotationName = typeSimplifier.simplify(annotationElement.asType());
     vars.className = generatedClassName;
     vars.imports = typeSimplifier.typesToImport();
-    vars.generated = typeSimplifier.simplify(getTypeMirror(Generated.class));
+    vars.generated = getGeneratedTypeName(typeSimplifier);
     vars.arrays = typeSimplifier.simplify(getTypeMirror(Arrays.class));
     vars.members = members;
     vars.params = parameters;
@@ -190,6 +190,15 @@ public class AutoAnnotationProcessor extends AbstractProcessor {
     writeSourceFile(fullName, text, methodClass);
   }
 
+  private String getGeneratedTypeName(TypeSimplifier typeSimplifier) {
+    TypeElement generatedTypeElement =
+        processingEnv.getElementUtils().getTypeElement("javax.annotation.Generated");
+    if (generatedTypeElement == null) {
+      return "";
+    }
+    return typeSimplifier.simplify(generatedTypeElement.asType());
+  }
+
   /**
    * 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
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 9617a201..629fe166 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
@@ -44,7 +44,8 @@ class AutoAnnotationTemplateVars extends TemplateVars {
   SortedSet<String> imports;
 
   /**
-   * The spelling of the javax.annotation.Generated class: Generated or javax.annotation.Generated.
+   * The spelling of the {@code Generated} class: {@code Generated} or {@code
+   * javax.annotation.Generated}. Empty if the class is not available.
    */
   String generated;
 
diff --git a/value/src/main/java/com/google/auto/value/processor/AutoValueTemplateVars.java b/value/src/main/java/com/google/auto/value/processor/AutoValueTemplateVars.java
index a9612f94..515652e4 100644
--- a/value/src/main/java/com/google/auto/value/processor/AutoValueTemplateVars.java
+++ b/value/src/main/java/com/google/auto/value/processor/AutoValueTemplateVars.java
@@ -53,7 +53,8 @@ class AutoValueTemplateVars extends TemplateVars {
   ImmutableSortedSet<String> imports;
 
   /**
-   * The spelling of the javax.annotation.Generated class: Generated or javax.annotation.Generated.
+   * The spelling of the {@code Generated} class: {@code Generated} or {@code
+   * javax.annotation.Generated}. Empty if the class is not available.
    */
   String generated;
 
diff --git a/value/src/main/java/com/google/auto/value/processor/GwtSerialization.java b/value/src/main/java/com/google/auto/value/processor/GwtSerialization.java
index 4ec17964..c61f06c1 100644
--- a/value/src/main/java/com/google/auto/value/processor/GwtSerialization.java
+++ b/value/src/main/java/com/google/auto/value/processor/GwtSerialization.java
@@ -205,8 +205,8 @@ class GwtSerialization {
     String serializerClass;
 
     /**
-     * The spelling of the javax.annotation.Generated class: Generated or
-     * javax.annotation.Generated.
+     * The spelling of the {@code Generated} class: {@code Generated} or {@code
+     * javax.annotation.Generated}. Empty if the class is not available.
      */
     String generated;
 
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 f4a321be..ccfc4a0e 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
@@ -25,7 +25,11 @@ package $pkg;
 import $i;
 #end
 
+#if (!$generated.empty)
 @${generated}("com.google.auto.value.processor.AutoAnnotationProcessor")
+#else
+// Generated by com.google.auto.value.processor.AutoAnnotationProcessor
+#end
 final class $className implements $annotationName {
 
 ## Fields
diff --git a/value/src/main/java/com/google/auto/value/processor/autovalue.vm b/value/src/main/java/com/google/auto/value/processor/autovalue.vm
index 65d1d2f7..ffbbf21e 100644
--- a/value/src/main/java/com/google/auto/value/processor/autovalue.vm
+++ b/value/src/main/java/com/google/auto/value/processor/autovalue.vm
@@ -21,8 +21,10 @@ ${gwtCompatibleAnnotation}
 #foreach ($a in $annotations)
 $a
 #end
-#if ($generated != "")
+#if (!$generated.empty)
 @${generated}("com.google.auto.value.processor.AutoValueProcessor")
+#else
+// Generated by com.google.auto.value.processor.AutoValueProcessor
 #end
 #if ($isFinal) final #else abstract #end class $subclass$formalTypes extends $origClass$actualTypes {
 
diff --git a/value/src/main/java/com/google/auto/value/processor/gwtserializer.vm b/value/src/main/java/com/google/auto/value/processor/gwtserializer.vm
index 66782738..e24ddbbb 100644
--- a/value/src/main/java/com/google/auto/value/processor/gwtserializer.vm
+++ b/value/src/main/java/com/google/auto/value/processor/gwtserializer.vm
@@ -22,7 +22,11 @@ import com.google.gwt.user.client.rpc.SerializationException;
 import com.google.gwt.user.client.rpc.SerializationStreamReader;
 import com.google.gwt.user.client.rpc.SerializationStreamWriter;
 
+#if (!$generated.empty)
 @${generated}("com.google.auto.value.processor.AutoValueProcessor")
+#else
+// Generated by com.google.auto.value.processor.AutoValueProcessor
+#end
 public final class $serializerClass$formalTypes extends CustomFieldSerializer<$subclass$actualTypes> {
 
   public static $formalTypes $subclass$actualTypes instantiate(