From d8df9fbb706a2e2823a8a3affb9beceea3feb4b4 Mon Sep 17 00:00:00 2001
From: Gengchen Tuo <gengchen.tuo@ibm.com>
Date: Wed, 11 May 2022 10:34:55 -0400
Subject: [PATCH 1/2] Tests for final fields of hidden class, regular class,
 and interface Make sure the final fields are not modifiable through
 reflection. And fix one typo in record field test.

Signed-off-by: Gengchen Tuo <gengchen.tuo@ibm.com>
---
 test/functional/Java15andUp/playlist.xml      |  44 ++++++-
 .../HiddenClassFinalFieldTests.java           | 118 ++++++++++++++++++
 .../test/records/RecordFinalFieldTests.java   |   4 +-
 ...gularClassAndInterfaceFinalFieldTests.java | 116 +++++++++++++++++
 test/functional/Java15andUp/testng.xml        |  12 +-
 5 files changed, 290 insertions(+), 4 deletions(-)
 create mode 100644 test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java
 create mode 100644 test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java

diff --git a/test/functional/Java15andUp/playlist.xml b/test/functional/Java15andUp/playlist.xml
index c88a57d45ba..0a6baaf8b40 100644
--- a/test/functional/Java15andUp/playlist.xml
+++ b/test/functional/Java15andUp/playlist.xml
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='UTF-8'?>
 <!--
-  Copyright (c) 2020, 2021 IBM Corp. and others
+  Copyright (c) 2020, 2022 IBM Corp. and others
 
   This program and the accompanying materials are made available under
   the terms of the Eclipse Public License 2.0 which accompanies this
@@ -61,4 +61,46 @@
 			<version>15+</version>
 		</versions>
 	</test>
+	<test>
+		<testCaseName>Jep371Tests</testCaseName>
+		<command>$(JAVA_COMMAND) $(JVM_OPTIONS) \
+			--add-exports=java.base/jdk.internal.misc=ALL-UNNAMED \
+			-cp $(Q)$(LIB_DIR)$(RESOURCES_DIR)$(P)$(TESTNG)$(P)$(TEST_RESROOT)$(D)GeneralTest.jar$(Q) \
+			-cp $(Q)$(LIB_DIR)$(D)asm.jar$(P)$(LIB_DIR)$(RESOURCES_DIR)$(P)$(TESTNG)$(P)$(TEST_RESROOT)$(D)GeneralTest.jar$(Q) \
+			org.testng.TestNG -d $(REPORTDIR) $(Q)$(TEST_RESROOT)$(D)testng.xml$(Q) -testnames Jep371Tests \
+			-groups $(TEST_GROUP) \
+			-excludegroups $(DEFAULT_EXCLUDE); \
+			$(TEST_STATUS)
+		</command>
+		<levels>
+			<level>sanity</level>
+		</levels>
+		<groups>
+			<group>functional</group>
+		</groups>
+		<versions>
+			<version>15+</version>
+		</versions>
+	</test>
+	<test>
+		<testCaseName>RegularClassAndInterfaceFinalFieldTests</testCaseName>
+		<command>$(JAVA_COMMAND) $(JVM_OPTIONS) \
+			--add-exports=java.base/jdk.internal.misc=ALL-UNNAMED \
+			-cp $(Q)$(LIB_DIR)$(RESOURCES_DIR)$(P)$(TESTNG)$(P)$(TEST_RESROOT)$(D)GeneralTest.jar$(Q) \
+			-cp $(Q)$(LIB_DIR)$(D)asm.jar$(P)$(LIB_DIR)$(RESOURCES_DIR)$(P)$(TESTNG)$(P)$(TEST_RESROOT)$(D)GeneralTest.jar$(Q) \
+			org.testng.TestNG -d $(REPORTDIR) $(Q)$(TEST_RESROOT)$(D)testng.xml$(Q) -testnames RegularClassAndInterfaceFinalFieldTests \
+			-groups $(TEST_GROUP) \
+			-excludegroups $(DEFAULT_EXCLUDE); \
+			$(TEST_STATUS)
+		</command>
+		<levels>
+			<level>sanity</level>
+		</levels>
+		<groups>
+			<group>functional</group>
+		</groups>
+		<versions>
+			<version>15+</version>
+		</versions>
+	</test>
 </playlist>
diff --git a/test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java b/test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java
new file mode 100644
index 00000000000..0a0a885306a
--- /dev/null
+++ b/test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java
@@ -0,0 +1,118 @@
+package org.openj9.test.hiddenclasses;
+
+/*******************************************************************************
+ * Copyright (c) 2022, 2022 IBM Corp. and others
+ *
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which accompanies this
+ * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
+ * or the Apache License, Version 2.0 which accompanies this distribution and
+ * is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * This Source Code may also be made available under the following
+ * Secondary Licenses when the conditions for such availability set
+ * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
+ * General Public License, version 2 with the GNU Classpath
+ * Exception [1] and GNU General Public License, version 2 with the
+ * OpenJDK Assembly Exception [2].
+ *
+ * [1] https://www.gnu.org/software/classpath/license.html
+ * [2] http://openjdk.java.net/legal/assembly-exception.html
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+ *******************************************************************************/
+
+import jdk.internal.misc.Unsafe;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.FieldVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.testng.annotations.Test;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+import java.lang.reflect.Field;
+
+import static org.objectweb.asm.Opcodes.*;
+
+@Test(groups = { "level.sanity" })
+public class HiddenClassFinalFieldTests {
+
+    static Unsafe unsafe = Unsafe.getUnsafe();
+
+    Class<?> makeHiddenClass() throws Exception {
+        MethodHandles.Lookup lookup = MethodHandles.lookup();
+
+        ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+        FieldVisitor fv;
+        MethodVisitor mv;
+        cw.visit(V1_8, ACC_PUBLIC | ACC_SUPER, "org/openj9/test/hiddenclasses/TestHiddenClass", null, "java/lang/Object", null);
+        {
+            fv = cw.visitField(ACC_PUBLIC | ACC_STATIC, "modifiableField", "Ljava/lang/String;", null, "old");
+            fv.visitEnd();
+        }
+        {
+            cw.visitField(ACC_PUBLIC | ACC_STATIC | ACC_FINAL, "finalField", "Ljava/lang/String;", null, "old");
+            fv.visitEnd();
+        }
+        {
+            mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
+            mv.visitCode();
+            mv.visitVarInsn(ALOAD, 0);
+            mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
+            mv.visitInsn(RETURN);
+            mv.visitMaxs(1, 1);
+            mv.visitEnd();
+        }
+        cw.visitEnd();
+
+        return lookup.defineHiddenClass(cw.toByteArray(), true, MethodHandles.Lookup.ClassOption.NESTMATE).lookupClass();
+    }
+
+    /* Final static fields in hidden classes are not modifiable through reflection. */
+    @Test(expectedExceptions = java.lang.IllegalAccessException.class)
+    public void test_javaLangReflectFieldSet_finalStaticHiddenClassField() throws Throwable {
+        Class<?> c = makeHiddenClass();
+
+        Object hiddenClassObject = c.getConstructor().newInstance();
+        Field finalHiddenClassField = hiddenClassObject.getClass().getDeclaredField("finalField");
+        finalHiddenClassField.setAccessible(true);
+        finalHiddenClassField.set(hiddenClassObject, "new");
+    }
+
+    /* Make sure non-final fields in hidden classes can still be modified. */
+    @Test
+    public void test_javaLangReflectFieldSet_StaticHiddenClassField() throws Throwable {
+        Class<?> c = makeHiddenClass();
+
+        Object hiddenClassObject = c.getConstructor().newInstance();
+        Field finalHiddenClassField = hiddenClassObject.getClass().getDeclaredField("modifiableField");
+        finalHiddenClassField.setAccessible(true);
+        finalHiddenClassField.set(hiddenClassObject, "new");
+    }
+
+    /* Check that Unsafe.staticFieldOffset supports hidden classes. */
+    @Test
+    public void test_jdkInternalMiscUnsafe_staticFieldOffset() throws Throwable {
+        Class<?> c = makeHiddenClass();
+        Field finalHiddenClassField = c.getDeclaredField("finalField");
+        unsafe.staticFieldOffset(finalHiddenClassField);
+    }
+
+    /* Check that Unsafe.staticFieldBase supports hidden classes. */
+    @Test
+    public void test_jdkInternalMiscUnsafe_staticFieldBase() throws Throwable {
+        Class<?> c = makeHiddenClass();
+        Field finalHiddenClassField = c.getDeclaredField("finalField");
+        unsafe.staticFieldBase(finalHiddenClassField);
+    }
+
+    /* VarHandle.set is not supported for records. */
+    @Test(expectedExceptions = java.lang.UnsupportedOperationException.class)
+    public void test_javaLangInvokeMethodHandles_unreflectVarHandle_static() throws Throwable {
+        Class<?> c = makeHiddenClass();
+        Field finalHiddenClassField = c.getDeclaredField("finalField");
+        finalHiddenClassField.setAccessible(true);
+        VarHandle finalHiddenClassFieldHandle = MethodHandles.lookup().unreflectVarHandle(finalHiddenClassField);
+        finalHiddenClassFieldHandle.set("new");
+    }
+}
\ No newline at end of file
diff --git a/test/functional/Java15andUp/src/org/openj9/test/records/RecordFinalFieldTests.java b/test/functional/Java15andUp/src/org/openj9/test/records/RecordFinalFieldTests.java
index 19b86a2a9d8..88881f0f369 100644
--- a/test/functional/Java15andUp/src/org/openj9/test/records/RecordFinalFieldTests.java
+++ b/test/functional/Java15andUp/src/org/openj9/test/records/RecordFinalFieldTests.java
@@ -1,7 +1,7 @@
 package org.openj9.test.records;
 
 /*******************************************************************************
- * Copyright (c) 2020, 2020 IBM Corp. and others
+ * Copyright (c) 2020, 2022 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -129,7 +129,7 @@ public void test_jdkInternalMiscUnsafe_objectFieldOffset() throws Throwable {
         unsafe.objectFieldOffset(finalRecordField);
     }
 
-    /* Check that Unsafe.staticFieldBase supports records. */
+    /* Check that Unsafe.staticFieldOffset supports records. */
     @Test
     public void test_jdkInternalMiscUnsafe_staticFieldOffset() throws Throwable {
         Field finalRecordField = TestRecord.class.getDeclaredField("finalField");
diff --git a/test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java b/test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java
new file mode 100644
index 00000000000..8e8336760fb
--- /dev/null
+++ b/test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java
@@ -0,0 +1,116 @@
+package org.openj9.test.regularclassesandinterfaces;
+
+/*******************************************************************************
+ * Copyright (c) 2022, 2022 IBM Corp. and others
+ *
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which accompanies this
+ * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
+ * or the Apache License, Version 2.0 which accompanies this distribution and
+ * is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * This Source Code may also be made available under the following
+ * Secondary Licenses when the conditions for such availability set
+ * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
+ * General Public License, version 2 with the GNU Classpath
+ * Exception [1] and GNU General Public License, version 2 with the
+ * OpenJDK Assembly Exception [2].
+ *
+ * [1] https://www.gnu.org/software/classpath/license.html
+ * [2] http://openjdk.java.net/legal/assembly-exception.html
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+ *******************************************************************************/
+
+import jdk.internal.misc.Unsafe;
+import org.testng.annotations.Test;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+import java.lang.reflect.Field;
+
+@Test(groups = { "level.sanity" })
+public class RegularClassAndInterfaceFinalFieldTests {
+    static Unsafe unsafe = Unsafe.getUnsafe();
+
+    private class TestClass {
+        static String modifiableField = "old";
+        static final String finalField = "old";
+    }
+
+    private interface TestInterface {
+        String finalField = "old";
+    }
+
+    /* Final static fields in regular classes are not modifiable through reflection. */
+    @Test(expectedExceptions = java.lang.IllegalAccessException.class)
+    public void test_javaLangReflectFieldSet_finalStaticClassField() throws Throwable {
+        TestClass classObject = new TestClass();
+        Field finalClassField = classObject.getClass().getDeclaredField("finalField");
+        finalClassField.setAccessible(true);
+        finalClassField.set(classObject, "new");
+    }
+
+    /* Make sure non-final fields in regular classes can still be modified. */
+    @Test
+    public void test_javaLangReflectFieldSet_staticClassField() throws Throwable {
+        TestClass classObject = new TestClass();
+        Field classField = classObject.getClass().getDeclaredField("modifiableField");
+        classField.setAccessible(true);
+        classField.set(null, "new");
+    }
+
+    /* Final static fields in interface are not modifiable through reflection. */
+    @Test(expectedExceptions = java.lang.IllegalAccessException.class)
+    public void test_javaLangReflectFieldSet_finalStaticInterfaceField() throws Throwable {
+        Field finalInterfaceField = TestInterface.class.getDeclaredField("finalField");
+        finalInterfaceField.setAccessible(true);
+        finalInterfaceField.set(null, "new");
+    }
+
+    /* Check that Unsafe.staticFieldOffset supports regular classes. */
+    @Test
+    public void test_jdkInternalMiscUnsafe_staticClassFieldOffset() throws Throwable {
+        Field finalClassField = TestClass.class.getDeclaredField("finalField");
+        unsafe.staticFieldOffset(finalClassField);
+    }
+
+    /* Check that Unsafe.staticFieldBase supports regular classes. */
+    @Test
+    public void test_jdkInternalMiscUnsafe_staticClassFieldBase() throws Throwable {
+        Field finalClassField = TestClass.class.getDeclaredField("finalField");
+        unsafe.staticFieldBase(finalClassField);
+    }
+
+    /* Check that Unsafe.staticFieldOffset supports interfaces. */
+    @Test
+    public void test_jdkInternalMiscUnsafe_staticInterfaceFieldOffset() throws Throwable {
+        Field finalInterfaceField = TestInterface.class.getDeclaredField("finalField");
+        unsafe.staticFieldOffset(finalInterfaceField);
+    }
+
+    /* Check that Unsafe.staticFieldBase supports interfaces. */
+    @Test
+    public void test_jdkInternalMiscUnsafe_staticInterfaceFieldBase() throws Throwable {
+        Field finalInterfaceField = TestInterface.class.getDeclaredField("finalField");
+        unsafe.staticFieldBase(finalInterfaceField);
+    }
+
+    /* VarHandle.set is not supported for final field in regular classes. */
+    @Test(expectedExceptions = java.lang.UnsupportedOperationException.class)
+    public void test_javaLangInvokeMethodHandles_unreflectVarHandle_class_static() throws Throwable {
+        Field finalClassField = TestClass.class.getDeclaredField("finalField");
+        finalClassField.setAccessible(true);
+        VarHandle finalClassFieldHandle = MethodHandles.lookup().unreflectVarHandle(finalClassField);
+        finalClassFieldHandle.set("new");
+    }
+
+    /* VarHandle.set is not supported for final field in interfaces. */
+    @Test(expectedExceptions = java.lang.UnsupportedOperationException.class)
+    public void test_javaLangInvokeMethodHandles_unreflectVarHandle_interface_static() throws Throwable {
+        Field finalInterfaceField = TestInterface.class.getDeclaredField("finalField");
+        finalInterfaceField.setAccessible(true);
+        VarHandle finalInterfaceFieldHandle = MethodHandles.lookup().unreflectVarHandle(finalInterfaceField);
+        finalInterfaceFieldHandle.set("new");
+    }
+}
\ No newline at end of file
diff --git a/test/functional/Java15andUp/testng.xml b/test/functional/Java15andUp/testng.xml
index 6695a8abe7c..e8e49864a2a 100644
--- a/test/functional/Java15andUp/testng.xml
+++ b/test/functional/Java15andUp/testng.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
-  Copyright (c) 2020, 2020 IBM Corp. and others
+  Copyright (c) 2020, 2022 IBM Corp. and others
 
   This program and the accompanying materials are made available under
   the terms of the Eclipse Public License 2.0 which accompanies this
@@ -36,4 +36,14 @@
             <class name="org.openj9.test.records.RecordFinalFieldTests"/>
         </classes>
     </test>
+    <test name="Jep371Tests">
+        <classes>
+            <class name="org.openj9.test.hiddenclasses.HiddenClassFinalFieldTests"/>
+        </classes>
+    </test>
+    <test name="RegularClassAndInterfaceFinalFieldTests">
+        <classes>
+            <class name="org.openj9.test.regularclassesandinterfaces.RegularClassAndInterfaceFinalFieldTests"/>
+        </classes>
+    </test>
 </suite>

From 80f106151cdfc1262c22fcb46dc0436254b2eccb Mon Sep 17 00:00:00 2001
From: Gengchen Tuo <gengchen.tuo@ibm.com>
Date: Wed, 11 May 2022 11:50:09 -0400
Subject: [PATCH 2/2] Fix minor typo and format issue

Signed-off-by: Gengchen Tuo <gengchen.tuo@ibm.com>
---
 .../openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java | 4 ++--
 .../RegularClassAndInterfaceFinalFieldTests.java              | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java b/test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java
index 0a0a885306a..e6cf44a48b9 100644
--- a/test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java
+++ b/test/functional/Java15andUp/src/org/openj9/test/hiddenclasses/HiddenClassFinalFieldTests.java
@@ -106,7 +106,7 @@ public void test_jdkInternalMiscUnsafe_staticFieldBase() throws Throwable {
         unsafe.staticFieldBase(finalHiddenClassField);
     }
 
-    /* VarHandle.set is not supported for records. */
+    /* VarHandle.set is not supported for hidden classes. */
     @Test(expectedExceptions = java.lang.UnsupportedOperationException.class)
     public void test_javaLangInvokeMethodHandles_unreflectVarHandle_static() throws Throwable {
         Class<?> c = makeHiddenClass();
@@ -115,4 +115,4 @@ public void test_javaLangInvokeMethodHandles_unreflectVarHandle_static() throws
         VarHandle finalHiddenClassFieldHandle = MethodHandles.lookup().unreflectVarHandle(finalHiddenClassField);
         finalHiddenClassFieldHandle.set("new");
     }
-}
\ No newline at end of file
+}
diff --git a/test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java b/test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java
index 8e8336760fb..0e475343c33 100644
--- a/test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java
+++ b/test/functional/Java15andUp/src/org/openj9/test/regularclassesandinterfaces/RegularClassAndInterfaceFinalFieldTests.java
@@ -39,7 +39,7 @@ private class TestClass {
     }
 
     private interface TestInterface {
-        String finalField = "old";
+        static final String finalField = "old";
     }
 
     /* Final static fields in regular classes are not modifiable through reflection. */
@@ -113,4 +113,4 @@ public void test_javaLangInvokeMethodHandles_unreflectVarHandle_interface_static
         VarHandle finalInterfaceFieldHandle = MethodHandles.lookup().unreflectVarHandle(finalInterfaceField);
         finalInterfaceFieldHandle.set("new");
     }
-}
\ No newline at end of file
+}