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

*** 80,90 ****
  
      /** 1.10 local-variable type inference (var). */
      JDK10("10"),
  
      /** 1.11 covers the to be determined language features that will be added in JDK 11. */
!     JDK11("11");
  
      private static final Context.Key<Source> sourceKey = new Context.Key<>();
  
      public static Source instance(Context context) {
          Source instance = context.get(sourceKey);
--- 80,93 ----
  
      /** 1.10 local-variable type inference (var). */
      JDK10("10"),
  
      /** 1.11 covers the to be determined language features that will be added in JDK 11. */
!     JDK11("11"),
! 
!     /** 12 covers the to be determined language features that will be added in JDK 12. */
!     JDK12("12");
  
      private static final Context.Key<Source> sourceKey = new Context.Key<>();
  
      public static Source instance(Context context) {
          Source instance = context.get(sourceKey);
*** 127,136 ****
--- 130,140 ----
      public static Source lookup(String name) {
          return tab.get(name);
      }
  
      public Target requiredTarget() {
+         if (this.compareTo(JDK12) >= 0) return Target.JDK1_12;
          if (this.compareTo(JDK11) >= 0) return Target.JDK1_11;
          if (this.compareTo(JDK10) >= 0) return Target.JDK1_10;
          if (this.compareTo(JDK9) >= 0) return Target.JDK1_9;
          if (this.compareTo(JDK8) >= 0) return Target.JDK1_8;
          if (this.compareTo(JDK7) >= 0) return Target.JDK1_7;
*** 263,272 ****
--- 267,278 ----
              return RELEASE_9;
          case JDK10:
              return RELEASE_10;
          case JDK11:
              return RELEASE_11;
+         case JDK12:
+             return RELEASE_12;
          default:
              return null;
          }
      }
  }