--- old/src/java.compiler/share/classes/javax/lang/model/SourceVersion.java	2016-05-17 13:43:30.793508595 -0700
+++ new/src/java.compiler/share/classes/javax/lang/model/SourceVersion.java	2016-05-17 13:43:30.653508598 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2016, 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
@@ -55,7 +55,7 @@
      * 1.6: no changes
      * 1.7: diamond syntax, try-with-resources, etc.
      * 1.8: lambda expressions and default methods
-     * 9: To be determined
+     *   9: modules, small cleanups to 1.7 and 1.8 changes
      */
 
     /**
@@ -145,6 +145,9 @@
      * The version recognized by the Java Platform, Standard Edition
      * 9.
      *
+     * Additions in this release include modules and removal of a
+     * single underscore from the set of legal identifier names.
+     *
      * @since 9
      */
      RELEASE_9;
@@ -233,10 +236,10 @@
     }
 
     /**
-     *  Returns whether or not {@code name} is a syntactically valid
-     *  qualified name in the latest source version.  Unlike {@link
-     *  #isIdentifier isIdentifier}, this method returns {@code false}
-     *  for keywords and literals.
+     * Returns whether or not {@code name} is a syntactically valid
+     * qualified name in the latest source version.  Unlike {@link
+     * #isIdentifier isIdentifier}, this method returns {@code false}
+     * for keywords and literals.
      *
      * @param name the string to check
      * @return {@code true} if this string is a
@@ -244,10 +247,27 @@
      * @jls 6.2 Names and Identifiers
      */
     public static boolean isName(CharSequence name) {
+        return isName(name, latest());
+    }
+
+    /**
+     * Returns whether or not {@code name} is a syntactically valid
+     * qualified name in the given source version.  Unlike {@link
+     * #isIdentifier isIdentifier}, this method returns {@code false}
+     * for keywords and literals.
+     *
+     * @param name the string to check
+     * @param version the version to use
+     * @return {@code true} if this string is a
+     * syntactically valid name, {@code false} otherwise.
+     * @jls 6.2 Names and Identifiers
+     * @since 9
+     */
+    public static boolean isName(CharSequence name, SourceVersion version) {
         String id = name.toString();
 
         for(String s : id.split("\\.", -1)) {
-            if (!isIdentifier(s) || isKeyword(s))
+            if (!isIdentifier(s) || isKeyword(s, version))
                 return false;
         }
         return true;
@@ -268,7 +288,8 @@
             "class",    "finally",      "long",         "strictfp",     "volatile",
             "const",    "float",        "native",       "super",        "while",
             // literals
-            "null",     "true",         "false"
+            "null",     "true",         "false",
+            "_" // keyword as of 9
         };
         for(String kw : kws)
             s.add(kw);
@@ -276,8 +297,8 @@
     }
 
     /**
-     *  Returns whether or not {@code s} is a keyword or literal in the
-     *  latest source version.
+     * Returns whether or not {@code s} is a keyword or literal in the
+     * latest source version.
      *
      * @param s the string to check
      * @return {@code true} if {@code s} is a keyword or literal, {@code false} otherwise.
@@ -285,4 +306,22 @@
     public static boolean isKeyword(CharSequence s) {
         return keywords.contains(s.toString());
     }
+
+    /**
+     * Returns whether or not {@code s} is a keyword or literal in the
+     * given source version.
+     *
+     * @param s the string to check
+     * @param version the version to use
+     * @return {@code true} if {@code s} is a keyword or literal, {@code false} otherwise.
+     * @since 9
+     */
+    public static boolean isKeyword(CharSequence s, SourceVersion version) {
+        String id = s.toString();
+        if ("_".equals(id)) {
+            return version.compareTo(RELEASE_9) >= 0;
+        } else {
+            return keywords.contains(id);
+        }
+    }
 }