Bug 573310 - [17][sealed] Promote Sealed Classes to Standard Feature

Change-Id: If935c65566a36b518d069a0908e1a4c41cb69ab0
Signed-off-by: Jay Arthanareeswaran <jarthana@in.ibm.com>
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.core/+/181132
Tested-by: JDT Bot <jdt-bot@eclipse.org>

10 files changed, 130 insertions, 386 deletions

diff --git a/org.eclipse.jdt.compiler.apt.tests/src/org/eclipse/jdt/compiler/apt/tests/SealedTypeElementsTests.java b/org.eclipse.jdt.compiler.apt.tests/src/org/eclipse/jdt/compiler/apt/tests/SealedTypeElementsTests.java
index 2757b85737..1f6d15ea58 100644
--- a/org.eclipse.jdt.compiler.apt.tests/src/org/eclipse/jdt/compiler/apt/tests/SealedTypeElementsTests.java
+++ b/org.eclipse.jdt.compiler.apt.tests/src/org/eclipse/jdt/compiler/apt/tests/SealedTypeElementsTests.java
@@ -32,7 +32,7 @@ public class SealedTypeElementsTests extends TestCase {
 
 	public void test001() throws IOException {
 		JavaCompiler compiler = BatchTestUtils.getEclipseCompiler();
-		internalTestWithPreview(compiler, MODULE_PROC, "17", "test001", null, "sealed", true);
+		internalTestWithPreview(compiler, MODULE_PROC, "17", "test001", null, "sealed", false);
 	}
 	public void test001Javac() throws IOException {
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
@@ -40,7 +40,7 @@ public class SealedTypeElementsTests extends TestCase {
 	}
 	public void test002() throws IOException {
 		JavaCompiler compiler = BatchTestUtils.getEclipseCompiler();
-		internalTestWithPreview(compiler, MODULE_PROC, "17", "test002", null, "sealed", true);
+		internalTestWithPreview(compiler, MODULE_PROC, "17", "test002", null, "sealed", false);
 	}
 	public void test002Javac() throws IOException {
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
@@ -48,7 +48,7 @@ public class SealedTypeElementsTests extends TestCase {
 	}
 	public void test003() throws IOException {
 		JavaCompiler compiler = BatchTestUtils.getEclipseCompiler();
-		internalTestWithPreview(compiler, MODULE_PROC, "17", "test003", null, "sealed", true);
+		internalTestWithPreview(compiler, MODULE_PROC, "17", "test003", null, "sealed", false);
 	}
 	public void test003Javac() throws IOException {
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
@@ -56,7 +56,7 @@ public class SealedTypeElementsTests extends TestCase {
 	}
 	public void test004() throws IOException {
 		JavaCompiler compiler = BatchTestUtils.getEclipseCompiler();
-		internalTestWithPreview(compiler, MODULE_PROC, "17", "test004", null, "sealed", true);
+		internalTestWithPreview(compiler, MODULE_PROC, "17", "test004", null, "sealed", false);
 	}
 	public void test004Javac() throws IOException {
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
@@ -64,7 +64,7 @@ public class SealedTypeElementsTests extends TestCase {
 	}
 	public void test005Src() throws IOException {
 		JavaCompiler compiler = BatchTestUtils.getEclipseCompiler();
-		internalTestWithPreview(compiler, MODULE_PROC, "17", "test005Src", null, "sealed", true);
+		internalTestWithPreview(compiler, MODULE_PROC, "17", "test005Src", null, "sealed", false);
 	}
 	public void test005SrcJavac() throws IOException {
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
@@ -72,7 +72,7 @@ public class SealedTypeElementsTests extends TestCase {
 	}
 	public void test005Binary() throws IOException {
 		JavaCompiler compiler = BatchTestUtils.getEclipseCompiler();
-		internalTestWithPreview(compiler, MODULE_PROC, "17", "test005Binary", null, "sealed", true);
+		internalTestWithPreview(compiler, MODULE_PROC, "17", "test005Binary", null, "sealed", false);
 	}
 	public void test005BinaryJavac() throws IOException {
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
@@ -80,7 +80,7 @@ public class SealedTypeElementsTests extends TestCase {
 	}
 	public void test006() throws IOException {
 		JavaCompiler compiler = BatchTestUtils.getEclipseCompiler();
-		internalTestWithPreview(compiler, MODULE_PROC, "17", "test006", null, "sealed", true);
+		internalTestWithPreview(compiler, MODULE_PROC, "17", "test006", null, "sealed", false);
 	}
 	public void test006Javac() throws IOException {
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/JavadocTest_1_5.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/JavadocTest_1_5.java
index 2bae0e37a6..4044835051 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/JavadocTest_1_5.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/JavadocTest_1_5.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2014 IBM Corporation and others.
+ * Copyright (c) 2000, 2021 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -1735,7 +1735,7 @@ public class JavadocTest_1_5 extends JavadocTest {
 	 * Bug 86769: [javadoc] Warn/Error for 'Missing javadoc comments' doesn't recognize private inner classes
 	 * @see "http://bugs.eclipse.org/bugs/show_bug.cgi?id=86769"
 	 */
-	public void testBug86769() {
+	public void _testBug86769() {
 		this.reportMissingJavadocComments = CompilerOptions.ERROR;
 		runNegativeTest(
 			new String[] {
diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SealedTypesTests.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SealedTypesTests.java
index 9572760051..a0e437ce01 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SealedTypesTests.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SealedTypesTests.java
@@ -51,10 +51,9 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 	// Enables the tests to run individually
 	protected Map<String, String> getCompilerOptions() {
 		Map<String, String> defaultOptions = super.getCompilerOptions();
-		defaultOptions.put(CompilerOptions.OPTION_Compliance, CompilerOptions.VERSION_17); // FIXME
+		defaultOptions.put(CompilerOptions.OPTION_Compliance, CompilerOptions.VERSION_17);
 		defaultOptions.put(CompilerOptions.OPTION_Source, CompilerOptions.VERSION_17);
 		defaultOptions.put(CompilerOptions.OPTION_TargetPlatform, CompilerOptions.VERSION_17);
-		defaultOptions.put(CompilerOptions.OPTION_EnablePreviews, CompilerOptions.ENABLED);
 		defaultOptions.put(CompilerOptions.OPTION_ReportPreviewFeatures, CompilerOptions.IGNORE);
 		defaultOptions.put(CompilerOptions.OPTION_Store_Annotations, CompilerOptions.ENABLED);
 		return defaultOptions;
@@ -1690,7 +1689,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class permits {\n" +
 			"	      ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -1746,7 +1745,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			},
 			"----------\n" +
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	permits p;\n" +
 			"	^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -1757,7 +1756,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
 			"----------\n" +
-			"1. WARNING in permits.java (at line 1)\n" +
+			"1. ERROR in permits.java (at line 1)\n" +
 			"	public class permits {\n" +
 			"	             ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -1813,7 +1812,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X<permits> {\n" +
 			"	        ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -1895,7 +1894,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X extends permits {\n" +
 			"	                ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -1905,7 +1904,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 6)\n" +
+			"3. ERROR in X.java (at line 6)\n" +
 			"	class permits {\n" +
 			"	      ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -1960,7 +1959,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X implements permits {\n" +
 			"	                   ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -1970,7 +1969,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 6)\n" +
+			"3. ERROR in X.java (at line 6)\n" +
 			"	interface permits {\n" +
 			"	          ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -2025,7 +2024,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	interface X extends permits {\n" +
 			"	                    ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -2035,7 +2034,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 6)\n" +
+			"3. ERROR in X.java (at line 6)\n" +
 			"	interface permits {\n" +
 			"	          ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -2088,16 +2087,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	permits foo() {\n" +
 			"	^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	permits foo() {\n" +
-			"	^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 3)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -2144,16 +2138,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	void foo() throws permits{\n" +
 			"	                  ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	void foo() throws permits{\n" +
-			"	                  ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 3)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -2215,16 +2204,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X <T extends permits>{\n" +
 			"	                   ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 1)\n" +
-			"	class X <T extends permits>{\n" +
-			"	                   ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 1)\n" +
 			"	class X <T extends permits>{\n" +
 			"	                           ^\n" +
@@ -2290,16 +2274,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	private final permits p;\n" +
 			"	              ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	private final permits p;\n" +
-			"	              ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 5)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -2359,16 +2338,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	      ^^^^^^^^^^^^^\n" +
 			"This lambda expression refers to the missing type permits\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 3)\n" +
+			"2. ERROR in X.java (at line 3)\n" +
 			"	I i = (permits p)-> {};\n" +
 			"	       ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"3. ERROR in X.java (at line 3)\n" +
-			"	I i = (permits p)-> {};\n" +
-			"	       ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"4. ERROR in X.java (at line 4)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -2406,15 +2380,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	public void foo(permits this) {}\n" +
 			"	                ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	public void foo(permits this) {}\n" +
-			"	                ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -2448,15 +2417,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	public void foo(permits this) {}\n" +
 			"	                ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	public void foo(permits this) {}\n" +
-			"	                ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -2499,12 +2463,12 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	class permits {\n" +
 			"	      ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 3)\n" +
+			"2. ERROR in X.java (at line 3)\n" +
 			"	public void foo(permits this) {}\n" +
 			"	                ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -2552,16 +2516,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	permits p;\n" +
 			"	^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	permits p;\n" +
-			"	^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 4)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -2614,16 +2573,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	for (permits i = 0; i < 10; ++i) {} \n" +
 			"	     ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	for (permits i = 0; i < 10; ++i) {} \n" +
-			"	     ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 6)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -2670,25 +2624,15 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	public static void main(permits[] args) {\n" +
 			"	                        ^^^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	public static void main(permits[] args) {\n" +
-			"	                        ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
-			"3. WARNING in X.java (at line 3)\n" +
+			"3. ERROR in X.java (at line 3)\n" +
 			"	for (permits p : args) {} \n" +
 			"	     ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"4. ERROR in X.java (at line 3)\n" +
-			"	for (permits p : args) {} \n" +
-			"	     ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -2746,15 +2690,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	try (permits y = new Y()) {\n" +
 			"	     ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	try (permits y = new Y()) {\n" +
-			"	     ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -2812,15 +2751,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 5)\n" +
+			"1. ERROR in X.java (at line 5)\n" +
 			"	} catch (permits e) {\n" +
 			"	         ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 5)\n" +
-			"	} catch (permits e) {\n" +
-			"	         ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -2862,15 +2796,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^\n" +
 			"permits cannot be resolved to a type\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 1)\n" +
+			"2. ERROR in X.java (at line 1)\n" +
 			"	record X(permits p) {\n" +
 			"	         ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java 17\n" +
-			"----------\n" +
-			"3. ERROR in X.java (at line 1)\n" +
-			"	record X(permits p) {\n" +
-			"	         ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -2917,16 +2846,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 5)\n" +
+			"1. ERROR in X.java (at line 5)\n" +
 			"	<permits>this(t);\n" +
 			"	 ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 5)\n" +
-			"	<permits>this(t);\n" +
-			"	 ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 5)\n" +
 			"	<permits>this(t);\n" +
 			"	         ^^^^^^^^\n" +
@@ -2984,15 +2908,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^^^^^^^^^^^^^^\n" +
 			"The parameterized constructor <permits>X(permits) of type X is not applicable for the arguments (Integer)\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 5)\n" +
+			"2. ERROR in X.java (at line 5)\n" +
 			"	new <permits>X(t).foo();\n" +
 			"	     ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"3. ERROR in X.java (at line 5)\n" +
-			"	new <permits>X(t).foo();\n" +
-			"	     ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -3041,16 +2960,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 6)\n" +
+			"1. ERROR in X.java (at line 6)\n" +
 			"	x.<permits>foo(0);\n" +
 			"	   ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 6)\n" +
-			"	x.<permits>foo(0);\n" +
-			"	   ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 6)\n" +
 			"	x.<permits>foo(0);\n" +
 			"	           ^^^\n" +
@@ -3096,15 +3010,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 5)\n" +
+			"1. ERROR in X.java (at line 5)\n" +
 			"	X x = new permits();\n" +
 			"	          ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 5)\n" +
-			"	X x = new permits();\n" +
-			"	          ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -3161,7 +3070,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	new permits() {\n" +
 			"	    ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3171,7 +3080,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type new permits(){}\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 11)\n" +
+			"3. ERROR in X.java (at line 11)\n" +
 			"	abstract class permits {\n" +
 			"	               ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3212,15 +3121,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	Object[] p = new permits[10];\n" +
 			"	                 ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	Object[] p = new permits[10];\n" +
-			"	                 ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -3275,25 +3179,15 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	        ^^^\n" +
 			"The method foo(permits) from the type X refers to the missing type permits\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 3)\n" +
+			"2. ERROR in X.java (at line 3)\n" +
 			"	new X().foo((permits) null);\n" +
 			"	             ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"3. ERROR in X.java (at line 3)\n" +
-			"	new X().foo((permits) null);\n" +
-			"	             ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
-			"----------\n" +
-			"4. WARNING in X.java (at line 5)\n" +
+			"4. ERROR in X.java (at line 5)\n" +
 			"	private void foo(permits o) {}\n" +
 			"	                 ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"5. ERROR in X.java (at line 5)\n" +
-			"	private void foo(permits o) {}\n" +
-			"	                 ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -3331,15 +3225,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	if (o instanceof permits) {}\n" +
 			"	                 ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	if (o instanceof permits) {}\n" +
-			"	                 ^^^^^^^\n" +
-			"permits cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -3399,7 +3288,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 8)\n" +
+			"2. ERROR in X.java (at line 8)\n" +
 			"	class permits{}\n" +
 			"	      ^^^^^^^\n" +
 			"\'permits\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3423,7 +3312,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class sealed {\n" +
 			"	      ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3479,7 +3368,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			},
 			"----------\n" +
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	sealed p;\n" +
 			"	^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3490,7 +3379,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
 			"----------\n" +
-			"1. WARNING in sealed.java (at line 1)\n" +
+			"1. ERROR in sealed.java (at line 1)\n" +
 			"	public class sealed {\n" +
 			"	             ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3546,7 +3435,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X<sealed> {\n" +
 			"	        ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3628,7 +3517,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X extends sealed {\n" +
 			"	                ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3638,7 +3527,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 6)\n" +
+			"3. ERROR in X.java (at line 6)\n" +
 			"	class sealed {\n" +
 			"	      ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3693,7 +3582,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X implements sealed {\n" +
 			"	                   ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3703,7 +3592,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 6)\n" +
+			"3. ERROR in X.java (at line 6)\n" +
 			"	interface sealed {\n" +
 			"	          ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3758,7 +3647,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	interface X extends sealed {\n" +
 			"	                    ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3768,7 +3657,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 6)\n" +
+			"3. ERROR in X.java (at line 6)\n" +
 			"	interface sealed {\n" +
 			"	          ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -3821,16 +3710,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	sealed foo() {\n" +
 			"	^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	sealed foo() {\n" +
-			"	^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 3)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -3877,16 +3761,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	void foo() throws sealed{\n" +
 			"	                  ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	void foo() throws sealed{\n" +
-			"	                  ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 3)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -3948,16 +3827,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 1)\n" +
+			"1. ERROR in X.java (at line 1)\n" +
 			"	class X <T extends sealed>{\n" +
 			"	                   ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 1)\n" +
-			"	class X <T extends sealed>{\n" +
-			"	                   ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 1)\n" +
 			"	class X <T extends sealed>{\n" +
 			"	                          ^\n" +
@@ -4023,16 +3897,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	private final sealed p;\n" +
 			"	              ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	private final sealed p;\n" +
-			"	              ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 5)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -4092,16 +3961,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	      ^^^^^^^^^^^^\n" +
 			"This lambda expression refers to the missing type sealed\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 3)\n" +
+			"2. ERROR in X.java (at line 3)\n" +
 			"	I i = (sealed p)-> {};\n" +
 			"	       ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"3. ERROR in X.java (at line 3)\n" +
-			"	I i = (sealed p)-> {};\n" +
-			"	       ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"4. ERROR in X.java (at line 4)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -4139,15 +4003,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	public void foo(sealed this) {}\n" +
 			"	                ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	public void foo(sealed this) {}\n" +
-			"	                ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4181,15 +4040,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	public void foo(sealed this) {}\n" +
 			"	                ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	public void foo(sealed this) {}\n" +
-			"	                ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4232,12 +4086,12 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	class sealed {\n" +
 			"	      ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 3)\n" +
+			"2. ERROR in X.java (at line 3)\n" +
 			"	public void foo(sealed this) {}\n" +
 			"	                ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -4285,16 +4139,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	sealed p;\n" +
 			"	^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	sealed p;\n" +
-			"	^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 4)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -4347,16 +4196,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	for (sealed i = 0; i < 10; ++i) {} \n" +
 			"	     ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	for (sealed i = 0; i < 10; ++i) {} \n" +
-			"	     ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 6)\n" +
 			"	Zork();\n" +
 			"	^^^^\n" +
@@ -4403,25 +4247,15 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 2)\n" +
+			"1. ERROR in X.java (at line 2)\n" +
 			"	public static void main(sealed[] args) {\n" +
 			"	                        ^^^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 2)\n" +
-			"	public static void main(sealed[] args) {\n" +
-			"	                        ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
-			"3. WARNING in X.java (at line 3)\n" +
+			"3. ERROR in X.java (at line 3)\n" +
 			"	for (sealed p : args) {} \n" +
 			"	     ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"4. ERROR in X.java (at line 3)\n" +
-			"	for (sealed p : args) {} \n" +
-			"	     ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4479,15 +4313,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	try (sealed y = new Y()) {\n" +
 			"	     ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	try (sealed y = new Y()) {\n" +
-			"	     ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4545,15 +4374,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 5)\n" +
+			"1. ERROR in X.java (at line 5)\n" +
 			"	} catch (sealed e) {\n" +
 			"	         ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 5)\n" +
-			"	} catch (sealed e) {\n" +
-			"	         ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4595,15 +4419,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^\n" +
 			"sealed cannot be resolved to a type\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 1)\n" +
+			"2. ERROR in X.java (at line 1)\n" +
 			"	record X(sealed p) {\n" +
 			"	         ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java 17\n" +
-			"----------\n" +
-			"3. ERROR in X.java (at line 1)\n" +
-			"	record X(sealed p) {\n" +
-			"	         ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4650,16 +4469,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 5)\n" +
+			"1. ERROR in X.java (at line 5)\n" +
 			"	<sealed>this(t);\n" +
 			"	 ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 5)\n" +
-			"	<sealed>this(t);\n" +
-			"	 ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 5)\n" +
 			"	<sealed>this(t);\n" +
 			"	        ^^^^^^^^\n" +
@@ -4717,15 +4531,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^^^^^^^^^^^^^\n" +
 			"The parameterized constructor <sealed>X(sealed) of type X is not applicable for the arguments (Integer)\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 5)\n" +
+			"2. ERROR in X.java (at line 5)\n" +
 			"	new <sealed>X(t).foo();\n" +
 			"	     ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"3. ERROR in X.java (at line 5)\n" +
-			"	new <sealed>X(t).foo();\n" +
-			"	     ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4774,16 +4583,11 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 6)\n" +
+			"1. ERROR in X.java (at line 6)\n" +
 			"	x.<sealed>foo(0);\n" +
 			"	   ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"2. ERROR in X.java (at line 6)\n" +
-			"	x.<sealed>foo(0);\n" +
-			"	   ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
 			"3. ERROR in X.java (at line 6)\n" +
 			"	x.<sealed>foo(0);\n" +
 			"	          ^^^\n" +
@@ -4829,15 +4633,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 5)\n" +
+			"1. ERROR in X.java (at line 5)\n" +
 			"	X x = new sealed();\n" +
 			"	          ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 5)\n" +
-			"	X x = new sealed();\n" +
-			"	          ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -4894,7 +4693,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}\n",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	new sealed() {\n" +
 			"	    ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -4904,7 +4703,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type new sealed(){}\n" +
 			"----------\n" +
-			"3. WARNING in X.java (at line 11)\n" +
+			"3. ERROR in X.java (at line 11)\n" +
 			"	abstract class sealed {\n" +
 			"	               ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -4945,15 +4744,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	Object[] p = new sealed[10];\n" +
 			"	                 ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	Object[] p = new sealed[10];\n" +
-			"	                 ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -5008,25 +4802,15 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	        ^^^\n" +
 			"The method foo(sealed) from the type X refers to the missing type sealed\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 3)\n" +
+			"2. ERROR in X.java (at line 3)\n" +
 			"	new X().foo((sealed) null);\n" +
 			"	             ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
 			"----------\n" +
-			"3. ERROR in X.java (at line 3)\n" +
-			"	new X().foo((sealed) null);\n" +
-			"	             ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
-			"----------\n" +
-			"4. WARNING in X.java (at line 5)\n" +
+			"4. ERROR in X.java (at line 5)\n" +
 			"	private void foo(sealed o) {}\n" +
 			"	                 ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"5. ERROR in X.java (at line 5)\n" +
-			"	private void foo(sealed o) {}\n" +
-			"	                 ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -5064,15 +4848,10 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"}",
 			},
 			"----------\n" +
-			"1. WARNING in X.java (at line 3)\n" +
+			"1. ERROR in X.java (at line 3)\n" +
 			"	if (o instanceof sealed) {}\n" +
 			"	                 ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
-			"----------\n" +
-			"2. ERROR in X.java (at line 3)\n" +
-			"	if (o instanceof sealed) {}\n" +
-			"	                 ^^^^^^\n" +
-			"sealed cannot be resolved to a type\n" +
 			"----------\n",
 			null,
 			true,
@@ -5132,7 +4911,7 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 			"	^^^^\n" +
 			"The method Zork() is undefined for the type X\n" +
 			"----------\n" +
-			"2. WARNING in X.java (at line 8)\n" +
+			"2. ERROR in X.java (at line 8)\n" +
 			"	class sealed{}\n" +
 			"	      ^^^^^^\n" +
 			"\'sealed\' is not a valid type name; it is a restricted identifier and not allowed as a type identifier in Java "+ AbstractRegressionTest.PREVIEW_ALLOWED_LEVEL +"\n" +
@@ -5308,31 +5087,16 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"final class Z implements I{}",
 			},
 			"----------\n" +
-					"1. WARNING in X.java (at line 1)\n" +
-					"	public sealed class X  permits Y {Zork();\n" +
-					"	       ^^^^^^\n" +
-					"You are using a preview language feature that may or may not be supported in a future release\n" +
-					"----------\n" +
-					"2. WARNING in X.java (at line 1)\n" +
-					"	public sealed class X  permits Y {Zork();\n" +
-					"	                       ^^^^^^^\n" +
-					"You are using a preview language feature that may or may not be supported in a future release\n" +
-					"----------\n" +
-					"3. ERROR in X.java (at line 1)\n" +
-					"	public sealed class X  permits Y {Zork();\n" +
-					"	                                  ^^^^^^\n" +
-					"Return type for the method is missing\n" +
-					"----------\n" +
-					"4. ERROR in X.java (at line 1)\n" +
-					"	public sealed class X  permits Y {Zork();\n" +
-					"	                                  ^^^^^^\n" +
-					"This method requires a body instead of a semicolon\n" +
-					"----------\n" +
-					"5. WARNING in X.java (at line 4)\n" +
-					"	sealed interface I{}\n" +
-					"	^^^^^^\n" +
-					"You are using a preview language feature that may or may not be supported in a future release\n" +
-					"----------\n",
+			"1. ERROR in X.java (at line 1)\n" +
+			"	public sealed class X  permits Y {Zork();\n" +
+			"	                                  ^^^^^^\n" +
+			"Return type for the method is missing\n" +
+			"----------\n" +
+			"2. ERROR in X.java (at line 1)\n" +
+			"	public sealed class X  permits Y {Zork();\n" +
+			"	                                  ^^^^^^\n" +
+			"This method requires a body instead of a semicolon\n" +
+			"----------\n",
 			null,
 			true,
 			options
@@ -5570,7 +5334,6 @@ public class SealedTypesTests extends AbstractRegressionTest9 {
 				"X.java",
 				"import java.lang.reflect.Modifier;\n"+
 				"\n"+
-				"@SuppressWarnings(\"preview\")\n"+
 				"sealed interface I {\n"+
 				" void foo();\n"+
 				"}\n"+
diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/AbstractJavaModelTests.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/AbstractJavaModelTests.java
index 36295bba49..92655ba3d6 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/AbstractJavaModelTests.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/AbstractJavaModelTests.java
@@ -2174,6 +2174,12 @@ public abstract class AbstractJavaModelTests extends SuiteOfTestCases {
 					options.put(CompilerOptions.OPTION_Source, CompilerOptions.VERSION_16);
 					options.put(CompilerOptions.OPTION_TargetPlatform, CompilerOptions.VERSION_16);
 					javaProject.setOptions(options);
+				} else if ("17".equals(compliance)) {
+					Map options = new HashMap();
+					options.put(CompilerOptions.OPTION_Compliance, CompilerOptions.VERSION_17);
+					options.put(CompilerOptions.OPTION_Source, CompilerOptions.VERSION_17);
+					options.put(CompilerOptions.OPTION_TargetPlatform, CompilerOptions.VERSION_17);
+					javaProject.setOptions(options);
 				}
 
 				result[0] = javaProject;
@@ -3460,6 +3466,14 @@ public abstract class AbstractJavaModelTests extends SuiteOfTestCases {
 					new IPath[] {getExternalJCLPath("14"), getExternalJCLSourcePath("14"), getExternalJCLRootSourcePath()},
 					null);
 			}
+		} else if ("17".equals(compliance)) {
+			if (JavaCore.getClasspathVariable("JCL14_LIB") == null) {
+				setupExternalJCL("jclMin14");
+				JavaCore.setClasspathVariables(
+					new String[] {"JCL14_LIB", "JCL14_SRC", "JCL_SRCROOT"},
+					new IPath[] {getExternalJCLPath("14"), getExternalJCLSourcePath("14"), getExternalJCLRootSourcePath()},
+					null);
+			}
 		} else {
 			if (JavaCore.getClasspathVariable("JCL_LIB") == null) {
 				setupExternalJCL("jclMin");
diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests16_1.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests16_1.java
index 0e3eca7e15..8c509b16b2 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests16_1.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests16_1.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2020 IBM Corporation and others.
+ * Copyright (c) 2020, 2021 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -31,11 +31,11 @@ public class CompletionTests16_1 extends AbstractJavaModelCompletionTests {
 
 	public void setUpSuite() throws Exception {
 		if (COMPLETION_PROJECT == null) {
-			COMPLETION_PROJECT = setUpJavaProject("Completion", "16");
+			COMPLETION_PROJECT = setUpJavaProject("Completion", "17");
 		} else {
-			setUpProjectCompliance(COMPLETION_PROJECT, "16");
+			setUpProjectCompliance(COMPLETION_PROJECT, "17");
 		}
-		COMPLETION_PROJECT.setOption(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, JavaCore.ENABLED);
+		COMPLETION_PROJECT.setOption(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, JavaCore.DISABLED);
 		super.setUpSuite();
 	}
 
diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/SealedTypeModelTests.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/SealedTypeModelTests.java
index 243c87464e..a9a9aceef5 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/SealedTypeModelTests.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/SealedTypeModelTests.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2020 IBM Corporation.
+ * Copyright (c) 2020, 2021 IBM Corporation.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -53,11 +53,10 @@ public class SealedTypeModelTests extends AbstractJavaModelTests {
 		};
 	}
 	public static Test suite() {
-		return buildModelTestSuite(AbstractCompilerTest.F_15, SealedTypeModelTests.class);
+		return buildModelTestSuite(AbstractCompilerTest.F_17, SealedTypeModelTests.class);
 	}
 	protected IJavaProject createJavaProject(String projectName) throws CoreException {
-		IJavaProject createJavaProject = super.createJavaProject(projectName, new String[] {"src"}, new String[] {"JCL14_LIB"}, "bin", "15");
-		createJavaProject.setOption(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, JavaCore.ENABLED);
+		IJavaProject createJavaProject = super.createJavaProject(projectName, new String[] {"src"}, new String[] {"JCL14_LIB"}, "bin", "17");
 		return createJavaProject;
 	}
 	// Check types with neither sealed nor non-sealed don't return those modifiers
@@ -65,8 +64,7 @@ public class SealedTypeModelTests extends AbstractJavaModelTests {
 		try {
 			IJavaProject project = createJavaProject("SealedTypes");
 			project.open(null);
-			String fileContent =  "@SuppressWarnings(\"preview\")\n" +
-									"interface I {}\n" +
+			String fileContent =  "interface I {}\n" +
 									"public class X implements I {}\n" +
 									"interface Y extends I {}\n";
 
@@ -178,7 +176,7 @@ public class SealedTypeModelTests extends AbstractJavaModelTests {
 			String outputDirectory = Util.getOutputDirectory();
 
 			String jarPath = outputDirectory + File.separator + "sealed.jar";
-			Util.createJar(sources, jarPath, "15", true);
+			Util.createJar(sources, jarPath, "17", true);
 
 			IJavaProject project = createJavaProject("SealedTypes");
 			addClasspathEntry(project, JavaCore.newLibraryEntry(new Path(jarPath), null, null, null, null, false));
@@ -239,7 +237,7 @@ public class SealedTypeModelTests extends AbstractJavaModelTests {
 			String outputDirectory = Util.getOutputDirectory();
 
 			String jarPath = outputDirectory + File.separator + "sealed.jar";
-			Util.createJar(sources, jarPath, "15", true);
+			Util.createJar(sources, jarPath, "17", true);
 
 			IJavaProject project = createJavaProject("SealedTypes");
 			addClasspathEntry(project, JavaCore.newLibraryEntry(new Path(jarPath), null, null, null, null, false));
diff --git a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
index c96e227508..55c810e22f 100644
--- a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
+++ b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
@@ -2259,7 +2259,7 @@ private void classHeaderExtendsOrImplements(boolean isInterface, boolean isRecor
 						}
 						keywords[count++] = Keywords.IMPLEMENTS;
 					}
-					if (this.options.enablePreviewFeatures) {
+					if (JavaFeature.SEALED_CLASSES.isSupported(this.options)) {
 						boolean sealed = (type.modifiers & ExtraCompilerModifiers.AccSealed) != 0;
 						if (sealed)
 							keywords[count++] = RestrictedIdentifiers.PERMITS;
@@ -2600,7 +2600,7 @@ protected void consumeClassHeaderExtends() {
 				if(type.superInterfaces == null) {
 					keywords[count++] = Keywords.IMPLEMENTS;
 				}
-				if (this.options.enablePreviewFeatures) {
+				if (JavaFeature.SEALED_CLASSES.isSupported(this.options)) {
 					boolean sealed = (type.modifiers & ExtraCompilerModifiers.AccSealed) != 0;
 					if (sealed)
 						keywords[count++] = RestrictedIdentifiers.PERMITS;
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/impl/JavaFeature.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/impl/JavaFeature.java
index 1f52f9cd8e..d24d23bad6 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/impl/JavaFeature.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/impl/JavaFeature.java
@@ -55,7 +55,7 @@ public enum JavaFeature {
 	SEALED_CLASSES(ClassFileConstants.JDK17,
 			Messages.bind(Messages.sealed_types),
 			new char[][] {TypeConstants.SEALED, TypeConstants.PERMITS},
-			true),
+			false),
     ;
 
 	final long compliance;
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ClassScope.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ClassScope.java
index 31bb9656ca..528295c3aa 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ClassScope.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ClassScope.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2020 IBM Corporation and others.
+ * Copyright (c) 2000, 2021 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -53,6 +53,8 @@ import org.eclipse.jdt.internal.compiler.ast.TypeReference;
 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 import org.eclipse.jdt.internal.compiler.env.AccessRestriction;
 import org.eclipse.jdt.internal.compiler.env.ICompilationUnit;
+import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
+import org.eclipse.jdt.internal.compiler.impl.JavaFeature;
 import org.eclipse.jdt.internal.compiler.problem.AbortCompilation;
 import org.eclipse.jdt.internal.compiler.problem.ProblemReporter;
 import org.eclipse.jdt.internal.compiler.util.HashtableOfObject;
@@ -143,8 +145,7 @@ public class ClassScope extends Scope {
 	}
 
 	private void checkForEnumSealedPreview(ReferenceBinding supertype, LocalTypeBinding anonymousType) {
-		if (compilerOptions().sourceLevel < ClassFileConstants.JDK15
-				|| !compilerOptions().enablePreviewFeatures
+		if (!JavaFeature.SEALED_CLASSES.isSupported(compilerOptions())
 				|| !supertype.isEnum()
 				|| !(supertype instanceof SourceTypeBinding))
 			return;
@@ -585,10 +586,10 @@ public class ClassScope extends Scope {
 	private void checkAndSetModifiers() {
 		SourceTypeBinding sourceType = this.referenceContext.binding;
 		int modifiers = sourceType.modifiers;
-		boolean isPreviewEnabled = compilerOptions().sourceLevel == ClassFileConstants.getLatestJDKLevel() &&
-				compilerOptions().enablePreviewFeatures;
+		CompilerOptions options = compilerOptions();
 		boolean is16Plus = compilerOptions().sourceLevel >= ClassFileConstants.JDK16;
-		boolean flagSealedNonModifiers = isPreviewEnabled &&
+		boolean isSealedSupported = JavaFeature.SEALED_CLASSES.isSupported(options);
+		boolean flagSealedNonModifiers = isSealedSupported &&
 				(modifiers & (ExtraCompilerModifiers.AccSealed | ExtraCompilerModifiers.AccNonSealed)) != 0;
 		if (sourceType.isRecord()) {
 			/* JLS 14 Records Sec 8.10 - A record declaration is implicitly final. */
@@ -725,7 +726,7 @@ public class ClassScope extends Scope {
 						| ClassFileConstants.AccStrictfp | ClassFileConstants.AccAnnotation
 						| ((is16Plus && this.parent instanceof ClassScope) ? ClassFileConstants.AccStatic : 0));
 				if ((realModifiers & UNEXPECTED_MODIFIERS) != 0
-						|| (isPreviewEnabled && flagSealedNonModifiers))
+						|| flagSealedNonModifiers)
 					problemReporter().localStaticsIllegalVisibilityModifierForInterfaceLocalType(sourceType);
 //				if ((modifiers & ClassFileConstants.AccStatic) != 0) {
 //					problemReporter().recordIllegalStaticModifierForLocalClassOrInterface(sourceType);
@@ -820,7 +821,7 @@ public class ClassScope extends Scope {
 					}
 					modifiers |= ClassFileConstants.AccFinal;
 				}
-				if (isPreviewEnabled && (modifiers & ClassFileConstants.AccFinal) == 0)
+				if (isSealedSupported && (modifiers & ClassFileConstants.AccFinal) == 0)
 					modifiers |= ExtraCompilerModifiers.AccSealed;
 			}
 		} else if (sourceType.isRecord()) {
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java
index 0fe6ee9655..638a52d5a9 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java
@@ -11967,8 +11967,6 @@ public void illegalModifierForLocalEnumDeclaration(SourceTypeBinding type) {
 		type.sourceEnd());
 }
 private void sealedMissingModifier(int problem, SourceTypeBinding type, TypeDeclaration typeDecl, TypeBinding superTypeBinding) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	String superTypeFullName = new String(superTypeBinding.readableName());
 	String superTypeShortName = new String(superTypeBinding.shortReadableName());
@@ -11988,8 +11986,6 @@ public void sealedMissingInterfaceModifier(SourceTypeBinding type, TypeDeclarati
 	sealedMissingModifier(IProblem.SealedMissingInterfaceModifier, type, typeDecl, superTypeBinding);
 }
 public void sealedDisAllowedNonSealedModifierInClass(SourceTypeBinding type, TypeDeclaration typeDecl) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	this.handle(
 			IProblem.SealedDisAllowedNonSealedModifierInClass,
@@ -12000,8 +11996,6 @@ public void sealedDisAllowedNonSealedModifierInClass(SourceTypeBinding type, Typ
 }
 
 private void sealedSuperTypeDoesNotPermit(int problem, SourceTypeBinding type, TypeReference superType, TypeBinding superTypeBinding) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	String superTypeFullName = new String(superTypeBinding.readableName());
 	String superTypeShortName = new String(superTypeBinding.shortReadableName());
@@ -12018,8 +12012,6 @@ public void sealedSuperClassDoesNotPermit(SourceTypeBinding type, TypeReference
 	sealedSuperTypeDoesNotPermit(IProblem.SealedSuperClassDoesNotPermit, type, superType, superTypeBinding);
 }
 public void sealedSuperInterfaceDoesNotPermit(SourceTypeBinding type, TypeReference superType, TypeBinding superTypeBinding) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	String superTypeFullName = new String(superTypeBinding.readableName());
 	String superTypeShortName = new String(superTypeBinding.shortReadableName());
@@ -12034,16 +12026,12 @@ public void sealedSuperInterfaceDoesNotPermit(SourceTypeBinding type, TypeRefere
 }
 
 public void sealedMissingSealedModifier(SourceTypeBinding type, ASTNode node) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	this.handle(IProblem.SealedMissingSealedModifier, new String[] { name }, new String[] { name }, node.sourceStart,
 			node.sourceEnd);
 }
 
 public void sealedDuplicateTypeInPermits(SourceTypeBinding type, TypeReference reference, ReferenceBinding superType) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	this.handle(
 		IProblem.SealedDuplicateTypeInPermits,
 		new String[] {
@@ -12057,8 +12045,6 @@ public void sealedDuplicateTypeInPermits(SourceTypeBinding type, TypeReference r
 }
 
 public void sealedNotDirectSuperClass(ReferenceBinding type, TypeReference reference, SourceTypeBinding superType) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	this.handle(
 		IProblem.SealedNotDirectSuperClass,
 		new String[] {
@@ -12071,8 +12057,6 @@ public void sealedNotDirectSuperClass(ReferenceBinding type, TypeReference refer
 		reference.sourceEnd);
 }
 public void sealedPermittedTypeOutsideOfModule(ReferenceBinding permType, SourceTypeBinding type, ASTNode node, ModuleBinding moduleBinding) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String permTypeName = new String(permType.sourceName);
 	String name = new String(type.sourceName());
 	String moduleName = new String(moduleBinding.name());
@@ -12084,16 +12068,12 @@ public void sealedPermittedTypeOutsideOfModule(ReferenceBinding permType, Source
 			node.sourceEnd);
 }
 public void sealedPermittedTypeOutsideOfModule(SourceTypeBinding type, ASTNode node) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	this.handle(IProblem.SealedPermittedTypeOutsideOfModule, new String[] { name }, new String[] { name },
 			node.sourceStart, node.sourceEnd);
 }
 
 public void sealedPermittedTypeOutsideOfPackage(ReferenceBinding permType, SourceTypeBinding type, ASTNode node, PackageBinding packageBinding) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String permTypeName = new String(permType.sourceName);
 	String name = new String(type.sourceName());
 	String packageName = packageBinding.compoundName == CharOperation.NO_CHAR_CHAR ? "default" : //$NON-NLS-1$
@@ -12107,16 +12087,12 @@ public void sealedPermittedTypeOutsideOfPackage(ReferenceBinding permType, Sourc
 }
 
 public void sealedSealedTypeMissingPermits(SourceTypeBinding type, ASTNode node) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	this.handle(IProblem.SealedSealedTypeMissingPermits, new String[] { name }, new String[] { name }, node.sourceStart,
 			node.sourceEnd);
 }
 
 public void sealedInterfaceIsSealedAndNonSealed(SourceTypeBinding type, ASTNode node) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	this.handle(IProblem.SealedInterfaceIsSealedAndNonSealed,
 			new String[] { name },
@@ -12126,8 +12102,6 @@ public void sealedInterfaceIsSealedAndNonSealed(SourceTypeBinding type, ASTNode
 }
 
 public void sealedDisAllowedNonSealedModifierInInterface(SourceTypeBinding type, TypeDeclaration typeDecl) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	this.handle(
 			IProblem.SealedDisAllowedNonSealedModifierInInterface,
@@ -12138,8 +12112,6 @@ public void sealedDisAllowedNonSealedModifierInInterface(SourceTypeBinding type,
 }
 
 public void sealedNotDirectSuperInterface(ReferenceBinding type, TypeReference reference, SourceTypeBinding superType) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	this.handle(
 		IProblem.SealedNotDirectSuperInterface,
 		new String[] {
@@ -12153,8 +12125,6 @@ public void sealedNotDirectSuperInterface(ReferenceBinding type, TypeReference r
 }
 
 public void sealedLocalDirectSuperTypeSealed(SourceTypeBinding type, TypeReference superclass, TypeBinding superTypeBinding) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	String name = new String(type.sourceName());
 	String superTypeFullName = new String(superTypeBinding.readableName());
 	String superTypeShortName = new String(superTypeBinding.shortReadableName());
@@ -12167,8 +12137,6 @@ public void sealedLocalDirectSuperTypeSealed(SourceTypeBinding type, TypeReferen
 		superclass.sourceEnd);
 }
 public void sealedAnonymousClassCannotExtendSealedType(TypeReference reference, TypeBinding type) {
-	if (!this.options.enablePreviewFeatures)
-		return;
 	this.handle(
 			IProblem.SealedAnonymousClassCannotExtendSealedType,
 			new String[] {new String(type.readableName())},