8348240: Remove SystemDictionaryShared::lookup_super_for_unregistered_class()

Reviewed-by: ccheung, coleenp

Author: iklam

src/hotspot/share/cds/classListParser.cpp

@@ -42,6 +42,7 @@
 #include "jvm.h"
 #include "logging/log.hpp"
 #include "logging/logTag.hpp"
+#include "memory/oopFactory.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/constantPool.inline.hpp"
 #include "runtime/atomic.hpp"
@@ -111,6 +112,12 @@ ClassListParser::~ClassListParser() {
   _instance = nullptr;
 }
 
+void ClassListParser::parse_classlist(const char* classlist_path, ParseMode parse_mode, TRAPS) {
+  UnregisteredClasses::initialize(CHECK);
+  ClassListParser parser(classlist_path, parse_mode);
+  parser.parse(THREAD);
+}
+
 void ClassListParser::parse(TRAPS) {
   for (; !_input_stream.done(); _input_stream.next()) {
     _line = _input_stream.current_line();
@@ -387,6 +394,19 @@ bool ClassListParser::parse_uint_option(const char* option_name, int* value) {
   return false;
 }
 
+objArrayOop ClassListParser::get_specified_interfaces(TRAPS) {
+  const int n = _interfaces->length();
+  if (n == 0) {
+    return nullptr;
+  } else {
+    objArrayOop array = oopFactory::new_objArray(vmClasses::Class_klass(), n, CHECK_NULL);
+    for (int i = 0; i < n; i++) {
+      array->obj_at_put(i, lookup_class_by_id(_interfaces->at(i))->java_mirror());
+    }
+    return array;
+  }
+}
+
 void ClassListParser::print_specified_interfaces() {
   const int n = _interfaces->length();
   jio_fprintf(defaultStream::error_stream(), "Currently specified interfaces[%d] = {\n", n);
@@ -514,7 +534,17 @@ InstanceKlass* ClassListParser::load_class_from_source(Symbol* class_name, TRAPS
 
   ResourceMark rm;
   char * source_path = os::strdup_check_oom(ClassLoader::uri_to_path(_source));
-  InstanceKlass* k = UnregisteredClasses::load_class(class_name, source_path, CHECK_NULL);
+  InstanceKlass* specified_super = lookup_class_by_id(_super);
+  Handle super_class(THREAD, specified_super->java_mirror());
+  objArrayOop r = get_specified_interfaces(CHECK_NULL);
+  objArrayHandle interfaces(THREAD, r);
+  InstanceKlass* k = UnregisteredClasses::load_class(class_name, source_path,
+                                                     super_class, interfaces, CHECK_NULL);
+  if (k->java_super() != specified_super) {
+    error("The specified super class %s (id %d) does not match actual super class %s",
+          specified_super->external_name(), _super,
+          k->java_super()->external_name());
+  }
   if (k->local_interfaces()->length() != _interfaces->length()) {
     print_specified_interfaces();
     print_actual_interfaces(k);
@@ -734,49 +764,6 @@ InstanceKlass* ClassListParser::lookup_class_by_id(int id) {
   return *klass_ptr;
 }
 
-
-InstanceKlass* ClassListParser::lookup_super_for_current_class(Symbol* super_name) {
-  if (!is_loading_from_source()) {
-    return nullptr;
-  }
-
-  InstanceKlass* k = lookup_class_by_id(super());
-  if (super_name != k->name()) {
-    error("The specified super class %s (id %d) does not match actual super class %s",
-          k->name()->as_klass_external_name(), super(),
-          super_name->as_klass_external_name());
-  }
-  return k;
-}
-
-InstanceKlass* ClassListParser::lookup_interface_for_current_class(Symbol* interface_name) {
-  if (!is_loading_from_source()) {
-    return nullptr;
-  }
-
-  const int n = _interfaces->length();
-  if (n == 0) {
-    error("Class %s implements the interface %s, but no interface has been specified in the input line",
-          _class_name, interface_name->as_klass_external_name());
-    ShouldNotReachHere();
-  }
-
-  int i;
-  for (i=0; i<n; i++) {
-    InstanceKlass* k = lookup_class_by_id(_interfaces->at(i));
-    if (interface_name == k->name()) {
-      return k;
-    }
-  }
-
-  // interface_name is not specified by the "interfaces:" keyword.
-  print_specified_interfaces();
-  error("The interface %s implemented by class %s does not match any of the specified interface IDs",
-        interface_name->as_klass_external_name(), _class_name);
-  ShouldNotReachHere();
-  return nullptr;
-}
-
 InstanceKlass* ClassListParser::find_builtin_class_helper(JavaThread* current, Symbol* class_name_symbol, oop class_loader_oop) {
   Handle class_loader(current, class_loader_oop);
   return SystemDictionary::find_instance_klass(current, class_name_symbol, class_loader);

src/hotspot/share/cds/classListParser.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 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
@@ -137,12 +137,10 @@ class ClassListParser : public StackObj {
   void print_diagnostic_info(outputStream* st, const char* msg, ...) ATTRIBUTE_PRINTF(3, 0);
   void constant_pool_resolution_warning(const char* msg, ...) ATTRIBUTE_PRINTF(2, 0);
   void error(const char* msg, ...) ATTRIBUTE_PRINTF(2, 0);
+  objArrayOop get_specified_interfaces(TRAPS);
 
 public:
-  static void parse_classlist(const char* classlist_path, ParseMode parse_mode, TRAPS) {
-    ClassListParser parser(classlist_path, parse_mode);
-    parser.parse(THREAD);
-  }
+  static void parse_classlist(const char* classlist_path, ParseMode parse_mode, TRAPS);
 
   static bool is_parsing_thread();
   static ClassListParser* instance() {
@@ -201,12 +199,6 @@ class ClassListParser : public StackObj {
   }
 
   bool is_loading_from_source();
-
-  // Look up the super or interface of the current class being loaded
-  // (in this->load_current_class()).
-  InstanceKlass* lookup_super_for_current_class(Symbol* super_name);
-  InstanceKlass* lookup_interface_for_current_class(Symbol* interface_name);
-
   static void populate_cds_indy_info(const constantPoolHandle &pool, int cp_index, CDSIndyInfo* cii, TRAPS);
 };
 #endif // SHARE_CDS_CLASSLISTPARSER_HPP

src/hotspot/share/cds/unregisteredClasses.cpp

@@ -28,7 +28,7 @@
 #include "classfile/classLoaderExt.hpp"
 #include "classfile/javaClasses.inline.hpp"
 #include "classfile/symbolTable.hpp"
-#include "classfile/systemDictionaryShared.hpp"
+#include "classfile/systemDictionary.hpp"
 #include "classfile/vmSymbols.hpp"
 #include "memory/oopFactory.hpp"
 #include "memory/resourceArea.hpp"
@@ -38,76 +38,82 @@
 #include "runtime/javaCalls.hpp"
 #include "services/threadService.hpp"
 
+InstanceKlass* UnregisteredClasses::_UnregisteredClassLoader_klass = nullptr;
+
+void UnregisteredClasses::initialize(TRAPS) {
+  if (_UnregisteredClassLoader_klass == nullptr) {
+    // no need for synchronization as this function is called single-threaded.
+    Symbol* klass_name = SymbolTable::new_symbol("jdk/internal/misc/CDS$UnregisteredClassLoader");
+    Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, CHECK);
+    _UnregisteredClassLoader_klass = InstanceKlass::cast(k);
+  }
+}
+
 // Load the class of the given name from the location given by path. The path is specified by
 // the "source:" in the class list file (see classListParser.cpp), and can be a directory or
 // a JAR file.
-InstanceKlass* UnregisteredClasses::load_class(Symbol* name, const char* path, TRAPS) {
+InstanceKlass* UnregisteredClasses::load_class(Symbol* name, const char* path,
+                                               Handle super_class, objArrayHandle interfaces, TRAPS) {
   assert(name != nullptr, "invariant");
   assert(CDSConfig::is_dumping_static_archive(), "this function is only used with -Xshare:dump");
 
   PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
                              THREAD->get_thread_stat()->perf_timers_addr(),
                              PerfClassTraceTime::CLASS_LOAD);
 
+  // Call CDS$UnregisteredClassLoader::load(String name, Class<?> superClass, Class<?>[] interfaces)
+  Symbol* methodName = SymbolTable::new_symbol("load");
+  Symbol* methodSignature = SymbolTable::new_symbol("(Ljava/lang/String;Ljava/lang/Class;[Ljava/lang/Class;)Ljava/lang/Class;");
   Symbol* path_symbol = SymbolTable::new_symbol(path);
-  Symbol* findClass = SymbolTable::new_symbol("findClass");
-  Handle url_classloader = get_url_classloader(path_symbol, CHECK_NULL);
+  Handle classloader = get_classloader(path_symbol, CHECK_NULL);
   Handle ext_class_name = java_lang_String::externalize_classname(name, CHECK_NULL);
 
   JavaValue result(T_OBJECT);
-  JavaCallArguments args(2);
-  args.set_receiver(url_classloader);
+  JavaCallArguments args(3);
+  args.set_receiver(classloader);
   args.push_oop(ext_class_name);
+  args.push_oop(super_class);
+  args.push_oop(interfaces);
   JavaCalls::call_virtual(&result,
-                          vmClasses::URLClassLoader_klass(),
-                          findClass,
-                          vmSymbols::string_class_signature(),
+                          UnregisteredClassLoader_klass(),
+                          methodName,
+                          methodSignature,
                           &args,
                           CHECK_NULL);
   assert(result.get_type() == T_OBJECT, "just checking");
   oop obj = result.get_oop();
   return InstanceKlass::cast(java_lang_Class::as_Klass(obj));
 }
 
-class URLClassLoaderTable : public ResourceHashtable<
+class UnregisteredClasses::ClassLoaderTable : public ResourceHashtable<
   Symbol*, OopHandle,
   137, // prime number
   AnyObj::C_HEAP> {};
 
-static URLClassLoaderTable* _url_classloader_table = nullptr;
+static UnregisteredClasses::ClassLoaderTable* _classloader_table = nullptr;
 
-Handle UnregisteredClasses::create_url_classloader(Symbol* path, TRAPS) {
+Handle UnregisteredClasses::create_classloader(Symbol* path, TRAPS) {
   ResourceMark rm(THREAD);
   JavaValue result(T_OBJECT);
   Handle path_string = java_lang_String::create_from_str(path->as_C_string(), CHECK_NH);
-  JavaCalls::call_static(&result,
-                         vmClasses::jdk_internal_loader_ClassLoaders_klass(),
-                         vmSymbols::toFileURL_name(),
-                         vmSymbols::toFileURL_signature(),
-                         path_string, CHECK_NH);
-  assert(result.get_type() == T_OBJECT, "just checking");
-  oop url_h = result.get_oop();
-  objArrayHandle urls = oopFactory::new_objArray_handle(vmClasses::URL_klass(), 1, CHECK_NH);
-  urls->obj_at_put(0, url_h);
-
-  Handle url_classloader = JavaCalls::construct_new_instance(
-                             vmClasses::URLClassLoader_klass(),
-                             vmSymbols::url_array_classloader_void_signature(),
-                             urls, Handle(), CHECK_NH);
-  return url_classloader;
+  Handle classloader = JavaCalls::construct_new_instance(
+                           UnregisteredClassLoader_klass(),
+                           vmSymbols::string_void_signature(),
+                           path_string, CHECK_NH);
+  return classloader;
 }
 
-Handle UnregisteredClasses::get_url_classloader(Symbol* path, TRAPS) {
-  if (_url_classloader_table == nullptr) {
-    _url_classloader_table = new (mtClass)URLClassLoaderTable();
+Handle UnregisteredClasses::get_classloader(Symbol* path, TRAPS) {
+  if (_classloader_table == nullptr) {
+    _classloader_table = new (mtClass)ClassLoaderTable();
   }
-  OopHandle* url_classloader_ptr = _url_classloader_table->get(path);
-  if (url_classloader_ptr != nullptr) {
-    return Handle(THREAD, (*url_classloader_ptr).resolve());
+  OopHandle* classloader_ptr = _classloader_table->get(path);
+  if (classloader_ptr != nullptr) {
+    return Handle(THREAD, (*classloader_ptr).resolve());
   } else {
-    Handle url_classloader = create_url_classloader(path, CHECK_NH);
-    _url_classloader_table->put(path, OopHandle(Universe::vm_global(), url_classloader()));
+    Handle classloader = create_classloader(path, CHECK_NH);
+    _classloader_table->put(path, OopHandle(Universe::vm_global(), classloader()));
     path->increment_refcount();
-    return url_classloader;
+    return classloader;
   }
 }

src/hotspot/share/cds/unregisteredClasses.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 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
@@ -25,15 +25,30 @@
 #ifndef SHARE_CDS_UNREGISTEREDCLASSES_HPP
 #define SHARE_CDS_UNREGISTEREDCLASSES_HPP
 
+#include "memory/allStatic.hpp"
 #include "runtime/handles.hpp"
 
+class InstanceKlass;
+class Symbol;
+
 class UnregisteredClasses: AllStatic {
 public:
-  static InstanceKlass* load_class(Symbol* h_name, const char* path, TRAPS);
+  static InstanceKlass* load_class(Symbol* h_name, const char* path,
+                                   Handle super_class, objArrayHandle interfaces,
+                                   TRAPS);
+  static void initialize(TRAPS);
+  static InstanceKlass* UnregisteredClassLoader_klass() {
+    return _UnregisteredClassLoader_klass;
+  }
+
+  class ClassLoaderTable;
 
 private:
-  static Handle create_url_classloader(Symbol* path, TRAPS);
-  static Handle get_url_classloader(Symbol* path, TRAPS);
+  // Don't put this in vmClasses as it's used only with CDS dumping.
+  static InstanceKlass* _UnregisteredClassLoader_klass;
+
+  static Handle create_classloader(Symbol* path, TRAPS);
+  static Handle get_classloader(Symbol* path, TRAPS);
 };
 
 #endif // SHARE_CDS_UNREGISTEREDCLASSES_HPP

src/hotspot/share/classfile/systemDictionary.cpp

@@ -423,16 +423,6 @@ InstanceKlass* SystemDictionary::resolve_with_circularity_detection(Symbol* clas
 
   assert(next_name != nullptr, "null superclass for resolving");
   assert(!Signature::is_array(next_name), "invalid superclass name");
-#if INCLUDE_CDS
-  if (CDSConfig::is_dumping_static_archive()) {
-    // Special processing for handling UNREGISTERED shared classes.
-    InstanceKlass* k = SystemDictionaryShared::lookup_super_for_unregistered_class(class_name,
-                           next_name, is_superclass);
-    if (k) {
-      return k;
-    }
-  }
-#endif // INCLUDE_CDS
 
   // If class_name is already loaded, just return the superclass or superinterface.
   // Make sure there's a placeholder for the class_name before resolving.

src/hotspot/share/classfile/systemDictionaryShared.cpp

@@ -35,6 +35,7 @@
 #include "cds/heapShared.hpp"
 #include "cds/metaspaceShared.hpp"
 #include "cds/runTimeClassInfo.hpp"
+#include "cds/unregisteredClasses.hpp"
 #include "classfile/classFileStream.hpp"
 #include "classfile/classLoader.hpp"
 #include "classfile/classLoaderData.inline.hpp"
@@ -352,6 +353,12 @@ bool SystemDictionaryShared::check_for_exclusion_impl(InstanceKlass* k) {
     }
   }
 
+  if (k == UnregisteredClasses::UnregisteredClassLoader_klass()) {
+    ResourceMark rm;
+    log_info(cds)("Skipping %s: used only when dumping CDS archive", k->name()->as_C_string());
+    return true;
+  }
+
   return false; // false == k should NOT be excluded
 }
 
@@ -470,45 +477,6 @@ bool SystemDictionaryShared::add_unregistered_class(Thread* current, InstanceKla
   return (klass == *v);
 }
 
-// This function is called to lookup the super/interfaces of shared classes for
-// unregistered loaders. E.g., SharedClass in the below example
-// where "super:" (and optionally "interface:") have been specified.
-//
-// java/lang/Object id: 0
-// Interface    id: 2 super: 0 source: cust.jar
-// SharedClass  id: 4 super: 0 interfaces: 2 source: cust.jar
-InstanceKlass* SystemDictionaryShared::lookup_super_for_unregistered_class(
-    Symbol* class_name, Symbol* super_name, bool is_superclass) {
-
-  assert(CDSConfig::is_dumping_static_archive(), "only when static dumping");
-
-  if (!ClassListParser::is_parsing_thread()) {
-    // Unregistered classes can be created only by ClassListParser::_parsing_thread.
-
-    return nullptr;
-  }
-
-  ClassListParser* parser = ClassListParser::instance();
-  if (parser == nullptr) {
-    // We're still loading the well-known classes, before the ClassListParser is created.
-    return nullptr;
-  }
-  if (class_name->equals(parser->current_class_name())) {
-    // When this function is called, all the numbered super and interface types
-    // must have already been loaded. Hence this function is never recursively called.
-    if (is_superclass) {
-      return parser->lookup_super_for_current_class(super_name);
-    } else {
-      return parser->lookup_interface_for_current_class(super_name);
-    }
-  } else {
-    // The VM is not trying to resolve a super type of parser->current_class_name().
-    // Instead, it's resolving an error class (because parser->current_class_name() has
-    // failed parsing or verification). Don't do anything here.
-    return nullptr;
-  }
-}
-
 void SystemDictionaryShared::set_shared_class_misc_info(InstanceKlass* k, ClassFileStream* cfs) {
   assert(CDSConfig::is_dumping_archive(), "sanity");
   assert(!is_builtin(k), "must be unregistered class");

src/hotspot/share/classfile/vmClassMacros.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 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
@@ -138,7 +138,6 @@
   /* support for CDS */                                                                                         \
   do_klass(ByteArrayInputStream_klass,                  java_io_ByteArrayInputStream                          ) \
   do_klass(URL_klass,                                   java_net_URL                                          ) \
-  do_klass(URLClassLoader_klass,                        java_net_URLClassLoader                               ) \
   do_klass(Enum_klass,                                  java_lang_Enum                                        ) \
   do_klass(Jar_Manifest_klass,                          java_util_jar_Manifest                                ) \
   do_klass(jdk_internal_loader_BuiltinClassLoader_klass,jdk_internal_loader_BuiltinClassLoader                ) \

src/hotspot/share/classfile/vmSymbols.hpp

@@ -124,7 +124,6 @@ class SerializeClosure;
   template(java_security_ProtectionDomain,            "java/security/ProtectionDomain")           \
   template(java_security_SecureClassLoader,           "java/security/SecureClassLoader")          \
   template(java_net_URL,                              "java/net/URL")                             \
-  template(java_net_URLClassLoader,                   "java/net/URLClassLoader")                  \
   template(java_util_jar_Manifest,                    "java/util/jar/Manifest")                   \
   template(java_io_ByteArrayInputStream,              "java/io/ByteArrayInputStream")             \
   template(java_io_Serializable,                      "java/io/Serializable")                     \
@@ -739,7 +738,6 @@ class SerializeClosure;
   template(runtimeSetup,                                    "runtimeSetup")                                       \
   template(toFileURL_name,                                  "toFileURL")                                          \
   template(toFileURL_signature,                             "(Ljava/lang/String;)Ljava/net/URL;")                 \
-  template(url_array_classloader_void_signature,            "([Ljava/net/URL;Ljava/lang/ClassLoader;)V")          \
                                                                                                                   \
   /* jcmd Thread.dump_to_file */                                                                                  \
   template(jdk_internal_vm_ThreadDumper,           "jdk/internal/vm/ThreadDumper")                                \

src/java.base/share/classes/jdk/internal/misc/CDS.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 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
@@ -31,6 +31,10 @@
 import java.io.InputStream;
 import java.io.IOException;
 import java.io.PrintStream;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.InvalidPathException;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.List;
@@ -337,4 +341,112 @@ private static String dumpSharedArchive(boolean isStatic, String fileName) throw
         System.out.println("The process was attached by jcmd and dumped a " + (isStatic ? "static" : "dynamic") + " archive " + archiveFilePath);
         return archiveFilePath;
     }
+
+    /**
+     * This class is used only by native JVM code at CDS dump time for loading
+     * "unregistered classes", which are archived classes that are intended to
+     * be loaded by custom class loaders during runtime.
+     * See src/hotspot/share/cds/unregisteredClasses.cpp.
+     */
+    private static class UnregisteredClassLoader extends URLClassLoader {
+        private String currentClassName;
+        private Class<?> currentSuperClass;
+        private Class<?>[] currentInterfaces;
+
+        /**
+         * Used only by native code. Construct an UnregisteredClassLoader for loading
+         * unregistered classes from the specified file. If the file doesn't exist,
+         * the exception will be caughted by native code which will print a warning message and continue.
+         *
+         * @param fileName path of the the JAR file to load unregistered classes from.
+         */
+        private UnregisteredClassLoader(String fileName) throws InvalidPathException, IOException {
+            super(toURLArray(fileName), /*parent*/null);
+            currentClassName = null;
+            currentSuperClass = null;
+            currentInterfaces = null;
+        }
+
+        private static URL[] toURLArray(String fileName) throws InvalidPathException, IOException {
+            if (!((new File(fileName)).exists())) {
+                throw new IOException("No such file: " + fileName);
+            }
+            return new URL[] {
+                // Use an intermediate File object to construct a URI/URL without
+                // authority component as URLClassPath can't handle URLs with a UNC
+                // server name in the authority component.
+                Path.of(fileName).toRealPath().toFile().toURI().toURL()
+            };
+        }
+
+
+        /**
+         * Load the class of the given <code>/name<code> from the JAR file that was given to
+         * the constructor of the current UnregisteredClassLoader instance. This class must be
+         * a direct subclass of <code>superClass</code>. This class must be declared to implement
+         * the specified <code>interfaces</code>.
+         * <p>
+         * This method must be called in a single threaded context. It will never be recursed (thus
+         * the asserts)
+         *
+         * @param name the name of the class to be loaded.
+         * @param superClass must not be null. The named class must have a super class.
+         * @param interfaces could be null if the named class does not implement any interfaces.
+         */
+        private Class<?> load(String name, Class<?> superClass, Class<?>[] interfaces)
+            throws ClassNotFoundException
+        {
+            assert currentClassName == null;
+            assert currentSuperClass == null;
+            assert currentInterfaces == null;
+
+            try {
+                currentClassName = name;
+                currentSuperClass = superClass;
+                currentInterfaces = interfaces;
+
+                return findClass(name);
+            } finally {
+                currentClassName = null;
+                currentSuperClass = null;
+                currentInterfaces = null;
+            }
+        }
+
+        /**
+         * This method must be called from inside the <code>load()</code> method. The <code>/name<code>
+         * can be only:
+         * <ul>
+         * <li> the <code>name</code> parameter for <code>load()</code>
+         * <li> the name of the <code>superClass</code> parameter for <code>load()</code>
+         * <li> the name of one of the interfaces in <code>interfaces</code> parameter for <code>load()</code>
+         * <ul>
+         *
+         * For all other cases, a <code>ClassNotFoundException</code> will be thrown.
+         */
+        protected Class<?> findClass(final String name)
+            throws ClassNotFoundException
+        {
+            Objects.requireNonNull(currentClassName);
+            Objects.requireNonNull(currentSuperClass);
+
+            if (name.equals(currentClassName)) {
+                // Note: the following call will call back to <code>this.findClass(name)</code> to
+                // resolve the super types of the named class.
+                return super.findClass(name);
+            }
+            if (name.equals(currentSuperClass.getName())) {
+                return currentSuperClass;
+            }
+            if (currentInterfaces != null) {
+                for (Class<?> c : currentInterfaces) {
+                    if (name.equals(c.getName())) {
+                        return c;
+                    }
+                }
+            }
+
+            throw new ClassNotFoundException(name);
+        }
+    }
 }

test/hotspot/jtreg/runtime/cds/appcds/customLoader/ClassListFormatE.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 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
@@ -49,14 +49,15 @@ public static void main(String[] args) throws Throwable {
         //----------------------------------------------------------------------
         // TESTGROUP E: super class and interfaces
         //----------------------------------------------------------------------
-        dumpShouldFail(
+        dumpShouldPass(
             "TESTCASE E1: missing interfaces: keyword",
             appJar, classlist(
                 "Hello",
                 "java/lang/Object id: 1",
                 "CustomLoadee2 id: 1 super: 1 source: " + customJarPath
             ),
-            "Class CustomLoadee2 implements the interface CustomInterface2_ia, but no interface has been specified in the input line");
+            "java.lang.NoClassDefFoundError: CustomInterface2_ia",
+            "Cannot find CustomLoadee2");
 
         dumpShouldFail(
             "TESTCASE E2: missing one interface",
@@ -67,7 +68,7 @@ appJar, classlist(
                 "CustomInterface2_ib id: 3 super: 1 source: " + customJarPath,
                 "CustomLoadee2 id: 4 super: 1 interfaces: 2 source: " + customJarPath
             ),
-            "The interface CustomInterface2_ib implemented by class CustomLoadee2 does not match any of the specified interface IDs");
+            "The number of interfaces (1) specified in class list does not match the class file (2)");
 
         dumpShouldFail(
             "TESTCASE E3: specifying an interface that's not implemented by the class",
@@ -101,5 +102,15 @@ appJar, classlist(
                 "CustomLoadee2 id: 5 super: 4 interfaces: 2 3 source: " + customJarPath
             ),
             "The specified super class CustomLoadee (id 4) does not match actual super class java.lang.Object");
+
+        dumpShouldPass(
+            "TESTCASE E6: JAR file doesn't exist",
+            appJar, classlist(
+                "Hello",
+                "java/lang/Object id: 1",
+                "NoSuchClass id: 2 super: 1 source: no_such_file.jar"
+            ),
+            "Cannot find NoSuchClass",
+            "java.io.IOException: No such file: no_such_file.jar");
     }
 }