diff -r ef331769d4ab -r bdbfa0115fc6 src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacProcessingEnvironment.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacProcessingEnvironment.java	Mon Apr 15 12:35:29 2019 -0700
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacProcessingEnvironment.java	Mon Apr 15 15:44:42 2019 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -188,6 +188,11 @@
 
     private final Context context;
 
+    /**
+     * Support for preview language features.
+     */
+    private final Preview preview;
+
     /** Get the JavacProcessingEnvironment instance for this context. */
     public static JavacProcessingEnvironment instance(Context context) {
         JavacProcessingEnvironment instance = context.get(JavacProcessingEnvironment.class);
@@ -236,6 +241,7 @@
         enter = Enter.instance(context);
         initialCompleter = ClassFinder.instance(context).getCompleter();
         chk = Check.instance(context);
+        preview = Preview.instance(context);
         initProcessorLoader();
     }
 
@@ -1675,6 +1681,11 @@
         return messages.getCurrentLocale();
     }
 
+    @DefinedBy(Api.ANNOTATION_PROCESSING)
+    public boolean isPreviewEnabled() {
+        return preview.isEnabled();
+    }
+
     public Set<Symbol.PackageSymbol> getSpecifiedPackages() {
         return specifiedPackages;
     }