8266822: Rename MetaspaceShared::is_old_class to be more explicit about what "old" means

Reviewed-by: iklam, minqi, coleenp

src/hotspot/share/cds/metaspaceShared.cpp

@@ -389,7 +389,7 @@ static void rewrite_nofast_bytecode(const methodHandle& method) {
 void MetaspaceShared::rewrite_nofast_bytecodes_and_calculate_fingerprints(Thread* thread, InstanceKlass* ik) {
   for (int i = 0; i < ik->methods()->length(); i++) {
     methodHandle m(thread, ik->methods()->at(i));
-    if (!is_old_class(ik)) {
+    if (!ik->has_old_class_version()) {
       rewrite_nofast_bytecode(m);
     }
     Fingerprinter fp(m);
@@ -574,31 +574,10 @@ public:
   ClassLoaderData* cld_at(int index) { return _loaded_cld.at(index); }
 };
 
-// Check if a class or its super class/interface is old.
-bool MetaspaceShared::is_old_class(InstanceKlass* ik) {
-  if (ik == NULL) {
-    return false;
-  }
-  if (ik->major_version() < 50 /*JAVA_6_VERSION*/) {
-    return true;
-  }
-  if (is_old_class(ik->java_super())) {
-    return true;
-  }
-  Array<InstanceKlass*>* interfaces = ik->local_interfaces();
-  int len = interfaces->length();
-  for (int i = 0; i < len; i++) {
-    if (is_old_class(interfaces->at(i))) {
-      return true;
-    }
-  }
-  return false;
-}
-
 bool MetaspaceShared::linking_required(InstanceKlass* ik) {
   // For static CDS dump, do not link old classes.
   // For dynamic CDS dump, only link classes loaded by the builtin class loaders.
-  return DumpSharedSpaces ? !MetaspaceShared::is_old_class(ik) : !ik->is_shared_unregistered_class();
+  return DumpSharedSpaces ? !ik->has_old_class_version() : !ik->is_shared_unregistered_class();
 }
 
 bool MetaspaceShared::link_class_for_cds(InstanceKlass* ik, TRAPS) {
@@ -778,7 +757,7 @@ bool MetaspaceShared::try_link_class(Thread* current, InstanceKlass* ik) {
   ExceptionMark em(current);
   Thread* THREAD = current; // For exception macros.
   Arguments::assert_is_dumping_archive();
-  if (ik->is_loaded() && !ik->is_linked() && !MetaspaceShared::is_old_class(ik) &&
+  if (ik->is_loaded() && !ik->is_linked() && !ik->has_old_class_version() &&
       !SystemDictionaryShared::has_class_failed_verification(ik)) {
     bool saved = BytecodeVerificationLocal;
     if (ik->is_shared_unregistered_class() && ik->class_loader() == NULL) {

src/hotspot/share/cds/metaspaceShared.hpp

@@ -137,7 +137,6 @@ public:
   static void link_and_cleanup_shared_classes(TRAPS) NOT_CDS_RETURN;
   static bool link_class_for_cds(InstanceKlass* ik, TRAPS) NOT_CDS_RETURN_(false);
   static bool linking_required(InstanceKlass* ik) NOT_CDS_RETURN_(false);
-  static bool is_old_class(InstanceKlass* ik) NOT_CDS_RETURN_(false);
 
 #if INCLUDE_CDS
   // Alignment for the 2 core CDS regions (RW/RO) only.

src/hotspot/share/classfile/systemDictionaryShared.cpp

@@ -1382,7 +1382,7 @@ bool SystemDictionaryShared::should_be_excluded(InstanceKlass* k) {
       warn_excluded(k, "Failed verification");
       return true;
     } else {
-      if (!MetaspaceShared::is_old_class(k)) {
+      if (!k->has_old_class_version()) {
         warn_excluded(k, "Not linked");
         return true;
       }
@@ -1397,7 +1397,7 @@ bool SystemDictionaryShared::should_be_excluded(InstanceKlass* k) {
     return true;
   }
 
-  if (MetaspaceShared::is_old_class(k) && k->is_linked()) {
+  if (k->has_old_class_version() && k->is_linked()) {
     warn_excluded(k, "Old class has been linked");
     return true;
   }

src/hotspot/share/interpreter/rewriter.cpp

@@ -571,7 +571,7 @@ void Rewriter::rewrite(InstanceKlass* klass, TRAPS) {
 #if INCLUDE_CDS
   if (klass->is_shared()) {
     assert(!klass->is_rewritten(), "rewritten shared classes cannot be rewritten again");
-    assert(MetaspaceShared::is_old_class(klass), "only shared old classes aren't rewritten");
+    assert(klass->has_old_class_version(), "only shared old classes aren't rewritten");
   }
 #endif // INCLUDE_CDS
   ResourceMark rm(THREAD);

src/hotspot/share/oops/instanceKlass.cpp

@@ -2429,7 +2429,7 @@ void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
 
 void InstanceKlass::remove_unshareable_info() {
 
-  if (MetaspaceShared::is_old_class(this)) {
+  if (has_old_class_version()) {
     // Set the old class bit.
     set_is_shared_old_klass();
   }
@@ -2568,6 +2568,28 @@ void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handl
   }
 }
 
+// Check if a class or any of its supertypes has a version older than 50.
+// CDS will not perform verification of old classes during dump time because
+// without changing the old verifier, the verification constraint cannot be
+// retrieved during dump time.
+// Verification of archived old classes will be performed during run time.
+bool InstanceKlass::has_old_class_version() const {
+  if (major_version() < 50 /*JAVA_6_VERSION*/) {
+    return true;
+  }
+  if (java_super() != NULL && java_super()->has_old_class_version()) {
+    return true;
+  }
+  Array<InstanceKlass*>* interfaces = local_interfaces();
+  int len = interfaces->length();
+  for (int i = 0; i < len; i++) {
+    if (interfaces->at(i)->has_old_class_version()) {
+      return true;
+    }
+  }
+  return false;
+}
+
 void InstanceKlass::set_shared_class_loader_type(s2 loader_type) {
   switch (loader_type) {
   case ClassLoader::BOOT_LOADER:

src/hotspot/share/oops/instanceKlass.hpp

@@ -1250,6 +1250,7 @@ public:
   virtual void remove_java_mirror();
   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
   void init_shared_package_entry();
+  bool has_old_class_version() const;
 
   jint compute_modifier_flags() const;
 

src/hotspot/share/oops/klassVtable.cpp

@@ -1094,8 +1094,8 @@ void itableMethodEntry::initialize(InstanceKlass* klass, Method* m) {
 #ifdef ASSERT
   if (MetaspaceShared::is_in_shared_metaspace((void*)&_method) &&
      !MetaspaceShared::remapped_readwrite() &&
-     !MetaspaceShared::is_old_class(m->method_holder()) &&
-     !MetaspaceShared::is_old_class(klass)) {
+     !m->method_holder()->has_old_class_version() &&
+     !klass->has_old_class_version()) {
     // At runtime initialize_itable is rerun as part of link_class_impl()
     // for a shared class loaded by the non-boot loader.
     // The dumptime itable method entry should be the same as the runtime entry.