8364187: Make getClassAccessFlagsRaw non-native

Reviewed-by: thartmann, rriggs, liach

Author: coleenp

src/hotspot/share/classfile/javaClasses.cpp

@@ -870,6 +870,7 @@ int java_lang_Class::_classRedefinedCount_offset;
 int java_lang_Class::_reflectionData_offset;
 int java_lang_Class::_modifiers_offset;
 int java_lang_Class::_is_primitive_offset;
+int java_lang_Class::_raw_access_flags_offset;
 
 bool java_lang_Class::_offsets_computed = false;
 GrowableArray<Klass*>* java_lang_Class::_fixup_mirror_list = nullptr;
@@ -1073,6 +1074,10 @@ void java_lang_Class::allocate_mirror(Klass* k, bool is_scratch, Handle protecti
   // Set the modifiers flag.
   u2 computed_modifiers = k->compute_modifier_flags();
   set_modifiers(mirror(), computed_modifiers);
+  // Set the raw access_flags, this is used by reflection instead of modifier flags.
+  // The Java code for array classes gets the access flags from the element type.
+  assert(!k->is_array_klass() || k->access_flags().as_unsigned_short() == 0, "access flags are not set for arrays");
+  set_raw_access_flags(mirror(), k->access_flags().as_unsigned_short());
 
   InstanceMirrorKlass* mk = InstanceMirrorKlass::cast(mirror->klass());
   assert(oop_size(mirror()) == mk->instance_size(k), "should have been set");
@@ -1378,6 +1383,8 @@ oop java_lang_Class::create_basic_type_mirror(const char* basic_type_name, Basic
   assert(static_oop_field_count(java_class) == 0, "should have been zeroed by allocation");
 #endif
   set_modifiers(java_class, JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC);
+  set_raw_access_flags(java_class, JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC);
+
   set_is_primitive(java_class);
   return java_class;
 }
@@ -1519,6 +1526,7 @@ oop java_lang_Class::primitive_mirror(BasicType t) {
   macro(_reflectionData_offset,      k, "reflectionData",      java_lang_ref_SoftReference_signature, false); \
   macro(_signers_offset,             k, "signers",             object_array_signature, false); \
   macro(_modifiers_offset,           k, vmSymbols::modifiers_name(), char_signature,    false); \
+  macro(_raw_access_flags_offset,    k, "classFileAccessFlags",      char_signature,    false); \
   macro(_protection_domain_offset,   k, "protectionDomain",    java_security_ProtectionDomain_signature,  false); \
   macro(_is_primitive_offset,        k, "primitive",           bool_signature,         false);
 
@@ -1564,6 +1572,16 @@ void java_lang_Class::set_modifiers(oop the_class_mirror, u2 value) {
   the_class_mirror->char_field_put(_modifiers_offset, value);
 }
 
+int java_lang_Class::raw_access_flags(oop the_class_mirror) {
+  assert(_raw_access_flags_offset != 0, "offsets should have been initialized");
+  return the_class_mirror->char_field(_raw_access_flags_offset);
+}
+
+void java_lang_Class::set_raw_access_flags(oop the_class_mirror, u2 value) {
+  assert(_raw_access_flags_offset != 0, "offsets should have been initialized");
+  the_class_mirror->char_field_put(_raw_access_flags_offset, value);
+}
+
 
 // Note: JDK1.1 and before had a privateInfo_offset field which was used for the
 //       platform thread structure, and a eetop offset which was used for thread

src/hotspot/share/classfile/javaClasses.hpp

@@ -258,6 +258,7 @@ class java_lang_Class : AllStatic {
   static int _reflectionData_offset;
   static int _modifiers_offset;
   static int _is_primitive_offset;
+  static int _raw_access_flags_offset;
 
   static bool _offsets_computed;
 
@@ -342,6 +343,9 @@ class java_lang_Class : AllStatic {
   static int modifiers(oop java_class);
   static void set_modifiers(oop java_class, u2 value);
 
+  static int raw_access_flags(oop java_class);
+  static void set_raw_access_flags(oop java_class, u2 value);
+
   static size_t oop_size(oop java_class);
   static void set_oop_size(HeapWord* java_class, size_t size);
   static int static_oop_field_count(oop java_class);

src/hotspot/share/classfile/vmIntrinsics.hpp

@@ -314,8 +314,6 @@ class methodHandle;
   do_intrinsic(_Class_cast,               java_lang_Class,        Class_cast_name, object_object_signature,      F_R)   \
    do_name(     Class_cast_name,                                 "cast")                                                \
                                                                                                                         \
-  do_intrinsic(_getClassAccessFlags,      reflect_Reflection,     getClassAccessFlags_name, class_int_signature, F_SN)  \
-   do_name(     getClassAccessFlags_name,                        "getClassAccessFlags")                                 \
   do_intrinsic(_getLength,                java_lang_reflect_Array, getLength_name, object_int_signature,         F_SN)  \
    do_name(     getLength_name,                                   "getLength")                                          \
                                                                                                                         \

src/hotspot/share/opto/c2compiler.cpp

@@ -760,7 +760,6 @@ bool C2Compiler::is_intrinsic_supported(vmIntrinsics::ID id) {
   case vmIntrinsics::_isInstance:
   case vmIntrinsics::_isHidden:
   case vmIntrinsics::_getSuperclass:
-  case vmIntrinsics::_getClassAccessFlags:
   case vmIntrinsics::_floatToRawIntBits:
   case vmIntrinsics::_floatToIntBits:
   case vmIntrinsics::_intBitsToFloat:

src/hotspot/share/opto/library_call.cpp

@@ -519,8 +519,7 @@ bool LibraryCallKit::try_to_inline(int predicate) {
 
   case vmIntrinsics::_isInstance:
   case vmIntrinsics::_isHidden:
-  case vmIntrinsics::_getSuperclass:
-  case vmIntrinsics::_getClassAccessFlags:      return inline_native_Class_query(intrinsic_id());
+  case vmIntrinsics::_getSuperclass:            return inline_native_Class_query(intrinsic_id());
 
   case vmIntrinsics::_floatToRawIntBits:
   case vmIntrinsics::_floatToIntBits:
@@ -4007,10 +4006,6 @@ bool LibraryCallKit::inline_native_Class_query(vmIntrinsics::ID id) {
     prim_return_value = null();
     return_type = TypeInstPtr::MIRROR->cast_to_ptr_type(TypePtr::BotPTR);
     break;
-  case vmIntrinsics::_getClassAccessFlags:
-    prim_return_value = intcon(JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC);
-    return_type = TypeInt::CHAR;
-    break;
   default:
     fatal_unexpected_iid(id);
     break;
@@ -4106,11 +4101,6 @@ bool LibraryCallKit::inline_native_Class_query(vmIntrinsics::ID id) {
     }
     break;
 
-  case vmIntrinsics::_getClassAccessFlags:
-    p = basic_plus_adr(kls, in_bytes(Klass::access_flags_offset()));
-    query_value = make_load(nullptr, p, TypeInt::CHAR, T_CHAR, MemNode::unordered);
-    break;
-
   default:
     fatal_unexpected_iid(id);
     break;

src/hotspot/share/opto/memnode.cpp

@@ -1981,13 +1981,11 @@ LoadNode::load_array_final_field(const TypeKlassPtr *tkls,
          "must not happen");
   if (tkls->offset() == in_bytes(Klass::access_flags_offset())) {
     // The field is Klass::_access_flags.  Return its (constant) value.
-    // (Folds up the 2nd indirection in Reflection.getClassAccessFlags(aClassConstant).)
     assert(Opcode() == Op_LoadUS, "must load an unsigned short from _access_flags");
     return TypeInt::make(klass->access_flags());
   }
   if (tkls->offset() == in_bytes(Klass::misc_flags_offset())) {
     // The field is Klass::_misc_flags.  Return its (constant) value.
-    // (Folds up the 2nd indirection in Reflection.getClassAccessFlags(aClassConstant).)
     assert(Opcode() == Op_LoadUB, "must load an unsigned byte from _misc_flags");
     return TypeInt::make(klass->misc_flags());
   }

src/hotspot/share/prims/jvm.cpp

@@ -1741,19 +1741,6 @@ JVM_ENTRY(jobjectArray, JVM_GetClassDeclaredConstructors(JNIEnv *env, jclass ofC
 }
 JVM_END
 
-JVM_ENTRY(jint, JVM_GetClassAccessFlags(JNIEnv *env, jclass cls))
-{
-  oop mirror = JNIHandles::resolve_non_null(cls);
-  if (java_lang_Class::is_primitive(mirror)) {
-    // Primitive type
-    return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
-  }
-
-  Klass* k = java_lang_Class::as_Klass(mirror);
-  return k->access_flags().as_class_flags();
-}
-JVM_END
-
 JVM_ENTRY(jboolean, JVM_AreNestMates(JNIEnv *env, jclass current, jclass member))
 {
   Klass* c = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(current));

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

@@ -240,7 +240,7 @@ private static void runtimeSetup() {
      * This constructor is not used and prevents the default constructor being
      * generated.
      */
-    private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim) {
+    private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) {
         // Initialize final field for classLoader.  The initialization value of non-null
         // prevents future JIT optimizations from assuming this final field is null.
         // The following assignments are done directly by the VM without calling this constructor.
@@ -249,6 +249,7 @@ private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, Protec
         modifiers = mods;
         protectionDomain = pd;
         primitive = isPrim;
+        classFileAccessFlags = flags;
     }
 
     /**
@@ -1012,6 +1013,7 @@ public Module getModule() {
     private transient Object classData; // Set by VM
     private transient Object[] signers; // Read by VM, mutable
     private final transient char modifiers;  // Set by the VM
+    private final transient char classFileAccessFlags;  // Set by the VM
     private final transient boolean primitive;  // Set by the VM if the Class is a primitive type.
 
     // package-private
@@ -1383,13 +1385,13 @@ public Set<AccessFlag> accessFlags() {
         // Location.CLASS allows SUPER and AccessFlag.MODULE which
         // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
         // and STATIC, which are not allowed on Location.CLASS.
-        // Use getClassAccessFlagsRaw to expose SUPER status.
+        // Use getClassFileAccessFlags to expose SUPER status.
         var location = (isMemberClass() || isLocalClass() ||
                         isAnonymousClass() || isArray()) ?
             AccessFlag.Location.INNER_CLASS :
             AccessFlag.Location.CLASS;
         return getReflectionFactory().parseAccessFlags((location == AccessFlag.Location.CLASS) ?
-                        getClassAccessFlagsRaw() : getModifiers(), location, this);
+                        getClassFileAccessFlags() : getModifiers(), location, this);
     }
 
     /**
@@ -4134,17 +4136,16 @@ int getClassFileVersion() {
 
     private native int getClassFileVersion0();
 
-    /*
-     * Return the access flags as they were in the class's bytecode, including
-     * the original setting of ACC_SUPER.
-     *
-     * If the class is an array type then the access flags of the element type is
-     * returned.  If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
-     */
-    private int getClassAccessFlagsRaw() {
-        Class<?> c = isArray() ? elementType() : this;
-        return c.getClassAccessFlagsRaw0();
-    }
-
-    private native int getClassAccessFlagsRaw0();
+     /**
+      * Return the access flags as they were in the class's bytecode, including
+      * the original setting of ACC_SUPER.
+      *
+      * If this {@code Class} object represents a primitive type or
+      * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
+      * {@code FINAL}.
+      * If this {@code Class} object represents an array type, return 0.
+      */
+     int getClassFileAccessFlags() {
+         return classFileAccessFlags;
+     }
 }

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

@@ -2022,6 +2022,9 @@ public byte[] getRawClassTypeAnnotations(Class<?> klass) {
             public byte[] getRawExecutableTypeAnnotations(Executable executable) {
                 return Class.getExecutableTypeAnnotationBytes(executable);
             }
+            public int getClassFileAccessFlags(Class<?> klass) {
+                return klass.getClassFileAccessFlags();
+            }
             public <E extends Enum<E>>
             E[] getEnumConstantsShared(Class<E> klass) {
                 return klass.getEnumConstantsShared();

src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java

@@ -112,6 +112,11 @@ public interface JavaLangAccess {
      */
     byte[] getRawExecutableTypeAnnotations(Executable executable);
 
+    /**
+     * Get the int value of the Class's class-file access flags.
+     */
+    int getClassFileAccessFlags(Class<?> klass);
+
     /**
      * Returns the elements of an enum class or null if the
      * Class object does not represent an enum type;