[GR-67325] Handle JDK 25+ class modifiers changes.

PullRequest: graal/21781

Author: javeleon

espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/impl/LinkedKlassFieldLayout.java

@@ -147,6 +147,11 @@ private static boolean storeAsFinal(ParserKlass klass, ParserField field) {
         if (klassType == Types.java_lang_System && (fieldName == Names.in || fieldName == Names.out || fieldName == Names.err)) {
             return false;
         }
+        // We're updating the class modifiers during redefinition if they change, so don't allow the
+        // compiler to fold the reads.
+        if (klassType == Types.java_lang_Class && fieldName == Names.modifiers) {
+            return false;
+        }
         return field.isFinal();
     }
 

espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/impl/ObjectKlass.java

@@ -1472,6 +1472,12 @@ public void redefineClass(ChangePacket packet, List<ObjectKlass> invalidatedClas
         getContext().getClassHierarchyOracle().registerNewKlassVersion(klassVersion);
 
         incrementKlassRedefinitionCount();
+        // Update the class modifiers in the guest for jdk 25+,
+        // but only call out to the guest if they have changed.
+        if (getContext().getJavaVersion().java25OrLater() && oldVersion.getClassModifiers() != klassVersion.getClassModifiers()) {
+            // update the guest value class modifiers
+            getMeta().java_lang_Class_modifiers.setChar(mirror(), (char) klassVersion.getClassModifiers());
+        }
         oldVersion.assumption.invalidate();
     }