8202113: Reflection API is causing caller classes to leak

Reviewed-by: alanb, plevart

src/java.base/share/classes/java/lang/reflect/AccessibleObject.java

@@ -564,7 +564,6 @@ public class AccessibleObject implements AnnotatedElement {
         throw new AssertionError("All subclasses should override this method");
     }
 
-
     // Shared access checking logic.
 
     // For non-public members or members in package-private classes,
@@ -674,4 +673,13 @@ public class AccessibleObject implements AnnotatedElement {
         }
         return printStackWhenAccessFails;
     }
+
+    /**
+     * Returns the root AccessibleObject; or null if this object is the root.
+     *
+     * All subclasses override this method.
+     */
+    AccessibleObject getRoot() {
+        throw new InternalError();
+    }
 }

src/java.base/share/classes/java/lang/reflect/Constructor.java

@@ -103,11 +103,8 @@ public final class Constructor<T> extends Executable {
     // occur in annotation code.
     private Constructor<T>      root;
 
-    /**
-     * Used by Excecutable for annotation sharing.
-     */
     @Override
-    Executable getRoot() {
+    Constructor<T> getRoot() {
         return root;
     }
 

src/java.base/share/classes/java/lang/reflect/Executable.java

@@ -55,11 +55,6 @@ public abstract class Executable extends AccessibleObject
      */
     abstract byte[] getAnnotationBytes();
 
-    /**
-     * Accessor method to allow code sharing
-     */
-    abstract Executable getRoot();
-
     /**
      * Does the Executable have generic information.
      */
@@ -602,7 +597,7 @@ public abstract class Executable extends AccessibleObject
         if ((declAnnos = declaredAnnotations) == null) {
             synchronized (this) {
                 if ((declAnnos = declaredAnnotations) == null) {
-                    Executable root = getRoot();
+                    Executable root = (Executable)getRoot();
                     if (root != null) {
                         declAnnos = root.declaredAnnotations();
                     } else {

src/java.base/share/classes/java/lang/reflect/Field.java

@@ -1128,6 +1128,11 @@ class Field extends AccessibleObject implements Member {
         }
     }
 
+    @Override
+    Field getRoot() {
+        return root;
+    }
+
     /**
      * @throws NullPointerException {@inheritDoc}
      * @since 1.5

src/java.base/share/classes/java/lang/reflect/Method.java

@@ -198,11 +198,8 @@ public final class Method extends Executable {
         checkCanSetAccessible(caller, clazz);
     }
 
-    /**
-     * Used by Excecutable for annotation sharing.
-     */
     @Override
-    Executable getRoot() {
+    Method getRoot() {
         return root;
     }
 

src/java.base/share/classes/java/lang/reflect/ReflectAccess.java

@@ -154,4 +154,9 @@ class ReflectAccess implements jdk.internal.reflect.LangReflectAccess {
     public <T> Constructor<T> copyConstructor(Constructor<T> arg) {
         return arg.copy();
     }
+
+    @SuppressWarnings("unchecked")
+    public <T extends AccessibleObject> T getRoot(T obj) {
+        return (T) obj.getRoot();
+    }
 }