src/java.base/share/classes/jdk/internal/classfile/impl/AccessFlagsImpl.java

*** 1,7 ***
  /*
!  * Copyright (c) 2022, 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
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ---
  /*
!  * Copyright (c) 2022, 2026, 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
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this

*** 23,40 ***
   * questions.
   */
  package jdk.internal.classfile.impl;
  
  import java.lang.classfile.AccessFlags;
  import java.lang.reflect.AccessFlag;
  import java.util.Set;
  
  public final class AccessFlagsImpl extends AbstractElement
          implements AccessFlags {
  
      private final AccessFlag.Location location;
      private final int flagsMask;
      private Set<AccessFlag> flags;
  
      public AccessFlagsImpl(AccessFlag.Location location, AccessFlag... flags) {
          this.location = location;
          this.flagsMask = Util.flagsToBits(location, flags);
          this.flags = Set.of(flags);
      }
  
      public AccessFlagsImpl(AccessFlag.Location location, int mask) {
          this.location = location;
          this.flagsMask = Util.checkFlags(mask);
      }
  
      @Override
      public int flagsMask() {
          return flagsMask;
      }
  
      @Override
      public Set<AccessFlag> flags() {
          if (flags == null)
!             flags = AccessFlag.maskToAccessFlags(flagsMask, location);
          return flags;
      }
  
      @Override
      public void writeTo(DirectClassBuilder builder) {
--- 23,62 ---
   * questions.
   */
  package jdk.internal.classfile.impl;
  
  import java.lang.classfile.AccessFlags;
+ import java.lang.classfile.ClassFile;
  import java.lang.reflect.AccessFlag;
+ import java.lang.reflect.ClassFileFormatVersion;
  import java.util.Set;
  
+ import jdk.internal.misc.VM;
+ 
  public final class AccessFlagsImpl extends AbstractElement
          implements AccessFlags {
  
      private final AccessFlag.Location location;
      private final int flagsMask;
+     private final ClassFileFormatVersion formatVersion;
      private Set<AccessFlag> flags;
  
      public AccessFlagsImpl(AccessFlag.Location location, AccessFlag... flags) {
          this.location = location;
          this.flagsMask = Util.flagsToBits(location, flags);
          this.flags = Set.of(flags);
+         this.formatVersion = ClassFileFormatVersion.latest();
      }
  
      public AccessFlagsImpl(AccessFlag.Location location, int mask) {
+         this(location, mask, ClassFileFormatVersion.latest());
+     }
+ 
+     public AccessFlagsImpl(AccessFlag.Location location, int mask, int version) {
+         int major = version & 0xFFFF;
+         int minor = version >>> Character.SIZE;
+ 
+         ClassFileFormatVersion cffv = minor == ClassFile.PREVIEW_MINOR_VERSION
+                 ? ClassFileFormatVersion.CURRENT_PREVIEW_FEATURES // Try to guess for older preview features
+                 : VM.isSupportedClassFileVersion(major, minor) ? ClassFileFormatVersion.fromMajor(major)
+                                                                : ClassFileFormatVersion.latest(); // Fallback
+         this(location, mask, cffv);
+     }
+ 
+     private AccessFlagsImpl(AccessFlag.Location location, int mask, ClassFileFormatVersion version) {
          this.location = location;
          this.flagsMask = Util.checkFlags(mask);
+         this.formatVersion = version;
      }
  
      @Override
      public int flagsMask() {
          return flagsMask;
      }
  
      @Override
      public Set<AccessFlag> flags() {
          if (flags == null)
!             flags = AccessFlag.maskToAccessFlags(flagsMask, location, formatVersion);
          return flags;
      }
  
      @Override
      public void writeTo(DirectClassBuilder builder) {