8349145: Make Class.getProtectionDomain() non-native

Reviewed-by: liach, dholmes, yzheng

src/java.base/share/classes/java/lang/Class.java

@@ -236,12 +236,13 @@ public final class Class<T> implements java.io.Serializable,
      * This constructor is not used and prevents the default constructor being
      * generated.
      */
-    private Class(ClassLoader loader, Class<?> arrayComponentType, int mods) {
+    private Class(ClassLoader loader, Class<?> arrayComponentType, int mods, ProtectionDomain pd) {
         // Initialize final field for classLoader.  The initialization value of non-null
         // prevents future JIT optimizations from assuming this final field is null.
         classLoader = loader;
         componentType = arrayComponentType;
         modifiers = mods;
+        protectionDomain = pd;
     }
 
     /**
@@ -2697,17 +2698,7 @@ public final class Class<T> implements java.io.Serializable,
         return true;
     }
 
-    /**
-     * Returns the {@code ProtectionDomain} of this class.
-     *
-     * @return the ProtectionDomain of this class
-     *
-     * @see java.security.ProtectionDomain
-     * @since 1.2
-     */
-    public ProtectionDomain getProtectionDomain() {
-        return protectionDomain();
-    }
+    private transient final ProtectionDomain protectionDomain;
 
     /** Holder for the protection domain returned when the internal domain is null */
     private static class Holder {
@@ -2719,21 +2710,22 @@ public final class Class<T> implements java.io.Serializable,
         }
     }
 
-    // package-private
-    ProtectionDomain protectionDomain() {
-        ProtectionDomain pd = getProtectionDomain0();
-        if (pd == null) {
+    /**
+     * Returns the {@code ProtectionDomain} of this class.
+     *
+     * @return the ProtectionDomain of this class
+     *
+     * @see java.security.ProtectionDomain
+     * @since 1.2
+     */
+    public ProtectionDomain getProtectionDomain() {
+        if (protectionDomain == null) {
             return Holder.allPermDomain;
         } else {
-            return pd;
+            return protectionDomain;
         }
     }
 
-    /**
-     * Returns the ProtectionDomain of this class.
-     */
-    private native ProtectionDomain getProtectionDomain0();
-
     /*
      * Returns the Class object for the named primitive type. Type parameter T
      * avoids redundant casts for trusted code.

src/java.base/share/classes/java/lang/System.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1994, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2148,7 +2148,7 @@ public final class System {
             }
 
             public ProtectionDomain protectionDomain(Class<?> c) {
-                return c.protectionDomain();
+                return c.getProtectionDomain();
             }
 
             public MethodHandle stringConcatHelper(String name, MethodType methodType) {

src/java.base/share/classes/jdk/internal/reflect/Reflection.java

@@ -56,7 +56,7 @@ public class Reflection {
         fieldFilterMap = Map.of(
             Reflection.class, ALL_MEMBERS,
             AccessibleObject.class, ALL_MEMBERS,
-            Class.class, Set.of("classLoader", "classData", "modifiers"),
+            Class.class, Set.of("classLoader", "classData", "modifiers", "protectionDomain"),
             ClassLoader.class, ALL_MEMBERS,
             Constructor.class, ALL_MEMBERS,
             Field.class, ALL_MEMBERS,