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

@@ -95,11 +95,17 @@
 
     /**
      * 14 covers the to be determined language features that will be
      * added in JDK 14.
      */
-    JDK14("14");
+    JDK14("14"),
+
+    /**
+     * 15 covers the to be determined language features that will be
+     * added in JDK 14.
+     */
+    JDK15("15");
 
     private static final Context.Key<Source> sourceKey = new Context.Key<>();
 
     public static Source instance(Context context) {
         Source instance = context.get(sourceKey);

@@ -146,10 +152,11 @@
     public boolean isSupported() {
         return this.compareTo(MIN) >= 0;
     }
 
     public Target requiredTarget() {
+        if (this.compareTo(JDK15) >= 0) return Target.JDK1_15;
         if (this.compareTo(JDK14) >= 0) return Target.JDK1_14;
         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;

@@ -194,14 +201,14 @@
         UNDERSCORE_IDENTIFIER(MIN, JDK8),
         PRIVATE_INTERFACE_METHODS(JDK9, Fragments.FeaturePrivateIntfMethods, DiagKind.PLURAL),
         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(JDK14, Fragments.FeatureMultipleCaseLabels, DiagKind.PLURAL),
-        SWITCH_RULE(JDK14, Fragments.FeatureSwitchRules, DiagKind.PLURAL),
-        SWITCH_EXPRESSION(JDK14, Fragments.FeatureSwitchExpressions, DiagKind.PLURAL),
-        TEXT_BLOCKS(JDK14, Fragments.FeatureTextBlocks, DiagKind.PLURAL);
+        SWITCH_MULTIPLE_CASE_LABELS(JDK15, Fragments.FeatureMultipleCaseLabels, DiagKind.PLURAL),
+        SWITCH_RULE(JDK15, Fragments.FeatureSwitchRules, DiagKind.PLURAL),
+        SWITCH_EXPRESSION(JDK15, Fragments.FeatureSwitchExpressions, DiagKind.PLURAL),
+        TEXT_BLOCKS(JDK15, Fragments.FeatureTextBlocks, DiagKind.PLURAL);
 
         enum DiagKind {
             NORMAL,
             PLURAL;
         }

@@ -286,10 +293,12 @@
             return RELEASE_12;
         case JDK13:
             return RELEASE_13;
         case JDK14:
             return RELEASE_14;
+        case JDK15:
+            return RELEASE_15;
         default:
             return null;
         }
     }
 }