src/share/classes/com/sun/tools/javac/code/Source.java

*** 65,76 ****
      JDK1_6("1.6"),
  
      /** 1.7 introduced try-with-resources, multi-catch, string switch, etc. */
      JDK1_7("1.7"),
  
!     /** 1.8 covers the to be determined language features that will be added in JDK 8. */
!     JDK1_8("1.8");
  
      private static final Context.Key<Source> sourceKey
          = new Context.Key<Source>();
  
      public static Source instance(Context context) {
--- 65,79 ----
      JDK1_6("1.6"),
  
      /** 1.7 introduced try-with-resources, multi-catch, string switch, etc. */
      JDK1_7("1.7"),
  
!     /** 1.8 lambda expressions and default methods. */
!     JDK1_8("1.8"),
! 
!     /** 1.9 covers the to be determined language features that will be added in JDK 9. */
!     JDK1_9("1.9");
  
      private static final Context.Key<Source> sourceKey
          = new Context.Key<Source>();
  
      public static Source instance(Context context) {
*** 85,116 ****
          return instance;
      }
  
      public final String name;
  
!     private static final Map<String,Source> tab = new HashMap<String,Source>();
      static {
          for (Source s : values()) {
              tab.put(s.name, s);
          }
          tab.put("5", JDK1_5); // Make 5 an alias for 1.5
          tab.put("6", JDK1_6); // Make 6 an alias for 1.6
          tab.put("7", JDK1_7); // Make 7 an alias for 1.7
          tab.put("8", JDK1_8); // Make 8 an alias for 1.8
      }
  
      private Source(String name) {
          this.name = name;
      }
  
!     public static final Source DEFAULT = JDK1_8;
  
      public static Source lookup(String name) {
          return tab.get(name);
      }
  
      public Target requiredTarget() {
          if (this.compareTo(JDK1_8) >= 0) return Target.JDK1_8;
          if (this.compareTo(JDK1_7) >= 0) return Target.JDK1_7;
          if (this.compareTo(JDK1_6) >= 0) return Target.JDK1_6;
          if (this.compareTo(JDK1_5) >= 0) return Target.JDK1_5;
          if (this.compareTo(JDK1_4) >= 0) return Target.JDK1_4;
--- 88,121 ----
          return instance;
      }
  
      public final String name;
  
!     private static final Map<String,Source> tab = new HashMap<>();
      static {
          for (Source s : values()) {
              tab.put(s.name, s);
          }
          tab.put("5", JDK1_5); // Make 5 an alias for 1.5
          tab.put("6", JDK1_6); // Make 6 an alias for 1.6
          tab.put("7", JDK1_7); // Make 7 an alias for 1.7
          tab.put("8", JDK1_8); // Make 8 an alias for 1.8
+         tab.put("9", JDK1_9); // Make 9 an alias for 1.9
      }
  
      private Source(String name) {
          this.name = name;
      }
  
!     public static final Source DEFAULT = JDK1_9;
  
      public static Source lookup(String name) {
          return tab.get(name);
      }
  
      public Target requiredTarget() {
+         if (this.compareTo(JDK1_9) >= 0) return Target.JDK1_9;
          if (this.compareTo(JDK1_8) >= 0) return Target.JDK1_8;
          if (this.compareTo(JDK1_7) >= 0) return Target.JDK1_7;
          if (this.compareTo(JDK1_6) >= 0) return Target.JDK1_6;
          if (this.compareTo(JDK1_5) >= 0) return Target.JDK1_5;
          if (this.compareTo(JDK1_4) >= 0) return Target.JDK1_4;
*** 241,250 ****
--- 246,257 ----
              return RELEASE_6;
          case JDK1_7:
              return RELEASE_7;
          case JDK1_8:
              return RELEASE_8;
+         case JDK1_9:
+             return RELEASE_8; // Adjust once RELEASE_9 exists
          default:
              return null;
          }
      }
  }