--- old/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java	2018-12-05 13:51:43.877560283 -0800
+++ new/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java	2018-12-05 13:51:43.677660275 -0800
@@ -85,7 +85,10 @@
     JDK11("11"),
 
     /** 12 covers the to be determined language features that will be added in JDK 12. */
-    JDK12("12");
+    JDK12("12"),
+
+    /** 13 covers the to be determined language features that will be added in JDK 13. */
+    JDK13("13");
 
     private static final Context.Key<Source> sourceKey = new Context.Key<>();
 
@@ -136,6 +139,7 @@
     }
 
     public Target requiredTarget() {
+        if (this.compareTo(JDK13) >= 0) return Target.JDK1_13;
         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;
@@ -182,10 +186,10 @@
         LOCAL_VARIABLE_TYPE_INFERENCE(JDK10),
         VAR_SYNTAX_IMPLICIT_LAMBDAS(JDK11, Fragments.FeatureVarSyntaxInImplicitLambda, DiagKind.PLURAL),
         IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES(JDK1_2, JDK8),
-        SWITCH_MULTIPLE_CASE_LABELS(JDK12, Fragments.FeatureMultipleCaseLabels, DiagKind.PLURAL),
-        SWITCH_RULE(JDK12, Fragments.FeatureSwitchRules, DiagKind.PLURAL),
-        SWITCH_EXPRESSION(JDK12, Fragments.FeatureSwitchExpressions, DiagKind.PLURAL),
-        RAW_STRING_LITERALS(JDK12, Fragments.FeatureRawStringLiterals, DiagKind.PLURAL);
+        SWITCH_MULTIPLE_CASE_LABELS(JDK13, Fragments.FeatureMultipleCaseLabels, DiagKind.PLURAL),
+        SWITCH_RULE(JDK13, Fragments.FeatureSwitchRules, DiagKind.PLURAL),
+        SWITCH_EXPRESSION(JDK13, Fragments.FeatureSwitchExpressions, DiagKind.PLURAL),
+        RAW_STRING_LITERALS(JDK13, Fragments.FeatureRawStringLiterals, DiagKind.PLURAL);
 
         enum DiagKind {
             NORMAL,
@@ -270,6 +274,8 @@
             return RELEASE_11;
         case JDK12:
             return RELEASE_12;
+        case JDK13:
+            return RELEASE_13;
         default:
             return null;
         }