1 /*
   2 * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
   3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4 *
   5 * This code is free software; you can redistribute it and/or modify it
   6 * under the terms of the GNU General Public License version 2 only, as
   7 * published by the Free Software Foundation.
   8 *
   9 * This code is distributed in the hope that it will be useful, but WITHOUT
  10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 * version 2 for more details (a copy is included in the LICENSE file that
  13 * accompanied this code).
  14 *
  15 * You should have received a copy of the GNU General Public License version
  16 * 2 along with this work; if not, write to the Free Software Foundation,
  17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18 *
  19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20 * or visit www.oracle.com if you need additional information or have any
  21 * questions.
  22 *
  23 */
  24 
  25 #include "cds/aotLogging.hpp"
  26 #include "cds/archiveBuilder.hpp"
  27 #include "cds/cdsConfig.hpp"
  28 #include "cds/metaspaceShared.hpp"
  29 #include "classfile/classFileParser.hpp"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/classLoaderData.inline.hpp"
  32 #include "classfile/classLoaderDataShared.hpp"
  33 #include "classfile/classLoaderExt.hpp"
  34 #include "classfile/javaAssertions.hpp"
  35 #include "classfile/javaClasses.hpp"
  36 #include "classfile/javaClasses.inline.hpp"
  37 #include "classfile/moduleEntry.hpp"
  38 #include "classfile/modules.hpp"
  39 #include "classfile/packageEntry.hpp"
  40 #include "classfile/stringTable.hpp"
  41 #include "classfile/symbolTable.hpp"
  42 #include "classfile/systemDictionary.hpp"
  43 #include "classfile/vmClasses.hpp"
  44 #include "classfile/vmSymbols.hpp"
  45 #include "jvm.h"
  46 #include "logging/log.hpp"
  47 #include "logging/logStream.hpp"
  48 #include "memory/resourceArea.hpp"
  49 #include "prims/jvmtiExport.hpp"
  50 #include "runtime/arguments.hpp"
  51 #include "runtime/globals_extension.hpp"
  52 #include "runtime/handles.inline.hpp"
  53 #include "runtime/javaCalls.hpp"
  54 #include "runtime/jniHandles.inline.hpp"
  55 #include "utilities/formatBuffer.hpp"
  56 #include "utilities/stringUtils.hpp"
  57 #include "utilities/utf8.hpp"
  58 
  59 static bool verify_module_name(const char *module_name, int len) {
  60   assert(module_name != nullptr, "invariant");
  61   return (len > 0 && len <= Symbol::max_length());
  62 }
  63 
  64 static bool verify_package_name(const char* package_name, int len) {
  65   assert(package_name != nullptr, "Package name derived from non-null jstring can't be null");
  66   return (len > 0 && len <= Symbol::max_length() &&
  67     ClassFileParser::verify_unqualified_name(package_name, len,
  68     ClassFileParser::LegalClass));
  69 }
  70 
  71 static char* get_module_name(oop module, int& len, TRAPS) {
  72   oop name_oop = java_lang_Module::name(module);
  73   if (name_oop == nullptr) {
  74     THROW_MSG_NULL(vmSymbols::java_lang_NullPointerException(), "Null module name");
  75   }
  76   size_t utf8_len;
  77   char* module_name = java_lang_String::as_utf8_string(name_oop, utf8_len);
  78   len = checked_cast<int>(utf8_len); // module names are < 64K
  79   if (!verify_module_name(module_name, len)) {
  80     THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),
  81                    err_msg("Invalid module name: %s", module_name));
  82   }
  83   return module_name;
  84 }
  85 
  86 static Symbol* as_symbol(jstring str_object) {
  87   if (str_object == nullptr) {
  88     return nullptr;
  89   }
  90   size_t len;
  91   char* str = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(str_object), len);
  92   return SymbolTable::new_symbol(str, checked_cast<int>(len));
  93 }
  94 
  95 ModuleEntryTable* Modules::get_module_entry_table(Handle h_loader) {
  96   // This code can be called during start-up, before the classLoader's classLoader data got
  97   // created.  So, call register_loader() to make sure the classLoader data gets created.
  98   ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader);
  99   return loader_cld->modules();
 100 }
 101 
 102 static PackageEntryTable* get_package_entry_table(Handle h_loader) {
 103   // This code can be called during start-up, before the classLoader's classLoader data got
 104   // created.  So, call register_loader() to make sure the classLoader data gets created.
 105   ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader);
 106   return loader_cld->packages();
 107 }
 108 
 109 static ModuleEntry* get_module_entry(Handle module, TRAPS) {
 110   if (!java_lang_Module::is_instance(module())) {
 111     THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),
 112                    "module is not an instance of type java.lang.Module");
 113   }
 114   return java_lang_Module::module_entry(module());
 115 }
 116 
 117 
 118 static PackageEntry* get_locked_package_entry(ModuleEntry* module_entry, const char* package_name, int len) {
 119   assert(Module_lock->owned_by_self(), "should have the Module_lock");
 120   assert(package_name != nullptr, "Precondition");
 121   TempNewSymbol pkg_symbol = SymbolTable::new_symbol(package_name, len);
 122   PackageEntryTable* package_entry_table = module_entry->loader_data()->packages();
 123   assert(package_entry_table != nullptr, "Unexpected null package entry table");
 124   PackageEntry* package_entry = package_entry_table->locked_lookup_only(pkg_symbol);
 125   assert(package_entry == nullptr || package_entry->module() == module_entry, "Unexpectedly found a package linked to another module");
 126   return package_entry;
 127 }
 128 
 129 static PackageEntry* get_package_entry_by_name(Symbol* package, Handle h_loader) {
 130   if (package != nullptr) {
 131     PackageEntryTable* const package_entry_table =
 132       get_package_entry_table(h_loader);
 133     assert(package_entry_table != nullptr, "Unexpected null package entry table");
 134     return package_entry_table->lookup_only(package);
 135   }
 136   return nullptr;
 137 }
 138 
 139 bool Modules::is_package_defined(Symbol* package, Handle h_loader) {
 140   PackageEntry* res = get_package_entry_by_name(package, h_loader);
 141   return res != nullptr;
 142 }
 143 
 144 // Converts the String oop to an internal package
 145 // Will use the provided buffer if it's sufficiently large, otherwise allocates
 146 // a resource array
 147 // The length of the resulting string will be assigned to utf8_len
 148 static const char* as_internal_package(oop package_string, char* buf, size_t buflen, int& utf8_len) {
 149   size_t full_utf8_len;
 150   char* package_name = java_lang_String::as_utf8_string_full(package_string, buf, buflen, full_utf8_len);
 151   utf8_len = checked_cast<int>(full_utf8_len); // package names are < 64K
 152 
 153   // Turn all '/'s into '.'s
 154   for (int index = 0; index < utf8_len; index++) {
 155     if (package_name[index] == JVM_SIGNATURE_DOT) {
 156       package_name[index] = JVM_SIGNATURE_SLASH;
 157     }
 158   }
 159   return package_name;
 160 }
 161 
 162 static void define_javabase_module(Handle module_handle, jstring version, jstring location,
 163                                    objArrayHandle pkgs, int num_packages, TRAPS) {
 164   ResourceMark rm(THREAD);
 165 
 166   // Obtain java.base's module version
 167   TempNewSymbol version_symbol = as_symbol(version);
 168 
 169   // Obtain java.base's location
 170   TempNewSymbol location_symbol = as_symbol(location);
 171 
 172   // Check that the packages are syntactically ok.
 173   char buf[128];
 174   GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);
 175   for (int x = 0; x < num_packages; x++) {
 176     oop pkg_str = pkgs->obj_at(x);
 177 
 178     if (pkg_str == nullptr || pkg_str->klass() != vmClasses::String_klass()) {
 179       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 180                 err_msg("Bad package name"));
 181     }
 182 
 183     int package_len;
 184     const char* package_name = as_internal_package(pkg_str, buf, sizeof(buf), package_len);
 185     if (!verify_package_name(package_name, package_len)) {
 186       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 187                 err_msg("Invalid package name: %s for module: " JAVA_BASE_NAME, package_name));
 188     }
 189     Symbol* pkg_symbol = SymbolTable::new_symbol(package_name, package_len);
 190     pkg_list->append(pkg_symbol);
 191   }
 192 
 193   // Validate java_base's loader is the boot loader.
 194   oop loader = java_lang_Module::loader(module_handle());
 195   if (loader != nullptr) {
 196     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 197               "Class loader must be the boot class loader");
 198   }
 199   Handle h_loader(THREAD, loader);
 200 
 201   // Ensure the boot loader's PackageEntryTable has been created
 202   PackageEntryTable* package_table = get_package_entry_table(h_loader);
 203   assert(pkg_list->length() == 0 || package_table != nullptr, "Bad package_table");
 204 
 205   // Ensure java.base's ModuleEntry has been created
 206   assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, "No ModuleEntry for " JAVA_BASE_NAME);
 207 
 208   bool duplicate_javabase = false;
 209   {
 210     MutexLocker m1(THREAD, Module_lock);
 211 
 212     if (ModuleEntryTable::javabase_defined()) {
 213       duplicate_javabase = true;
 214     } else {
 215 
 216       // Verify that all java.base packages created during bootstrapping are in
 217       // pkg_list.  If any are not in pkg_list, than a non-java.base class was
 218       // loaded erroneously pre java.base module definition.
 219       package_table->verify_javabase_packages(pkg_list);
 220 
 221       // loop through and add any new packages for java.base
 222       for (int x = 0; x < pkg_list->length(); x++) {
 223         // Some of java.base's packages were added early in bootstrapping, ignore duplicates.
 224         package_table->locked_create_entry_if_absent(pkg_list->at(x),
 225                                                      ModuleEntryTable::javabase_moduleEntry());
 226         assert(package_table->locked_lookup_only(pkg_list->at(x)) != nullptr,
 227                "Unable to create a " JAVA_BASE_NAME " package entry");
 228         // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of
 229         // the Symbol* that was created above for each package. The refcount was incremented
 230         // by SymbolTable::new_symbol and as well by the PackageEntry creation.
 231         pkg_list->at(x)->decrement_refcount();
 232       }
 233 
 234       // Finish defining java.base's ModuleEntry
 235       ModuleEntryTable::finalize_javabase(module_handle, version_symbol, location_symbol);
 236     }
 237   }
 238   if (duplicate_javabase) {
 239     THROW_MSG(vmSymbols::java_lang_InternalError(),
 240               "Module " JAVA_BASE_NAME " is already defined");
 241   }
 242 
 243   // Only the thread that actually defined the base module will get here,
 244   // so no locking is needed.
 245 
 246   // Patch any previously loaded class's module field with java.base's java.lang.Module.
 247   ModuleEntryTable::patch_javabase_entries(THREAD, module_handle);
 248 
 249   log_info(module, load)(JAVA_BASE_NAME " location: %s",
 250                          location_symbol != nullptr ? location_symbol->as_C_string() : "nullptr");
 251   log_debug(module)("define_javabase_module(): Definition of module: "
 252                     JAVA_BASE_NAME ", version: %s, location: %s, package #: %d",
 253                     version_symbol != nullptr ? version_symbol->as_C_string() : "nullptr",
 254                     location_symbol != nullptr ? location_symbol->as_C_string() : "nullptr",
 255                     pkg_list->length());
 256 
 257   // packages defined to java.base
 258   if (log_is_enabled(Trace, module)) {
 259     for (int x = 0; x < pkg_list->length(); x++) {
 260       log_trace(module)("define_javabase_module(): creation of package %s for module " JAVA_BASE_NAME,
 261                         (pkg_list->at(x))->as_C_string());
 262     }
 263   }
 264 }
 265 
 266 // Caller needs ResourceMark.
 267 static void throw_dup_pkg_exception(const char* module_name, PackageEntry* package, TRAPS) {
 268   const char* package_name = package->name()->as_C_string();
 269   if (package->module()->is_named()) {
 270     THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
 271       err_msg("Package %s for module %s is already in another module, %s, defined to the class loader",
 272               package_name, module_name, package->module()->name()->as_C_string()));
 273   } else {
 274     THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
 275       err_msg("Package %s for module %s is already in the unnamed module defined to the class loader",
 276               package_name, module_name));
 277   }
 278 }
 279 
 280 void Modules::define_module(Handle module, jboolean is_open, jstring version,
 281                             jstring location, jobjectArray packages, TRAPS) {
 282   ResourceMark rm(THREAD);
 283 
 284   if (module.is_null()) {
 285     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
 286   }
 287 
 288   if (!java_lang_Module::is_instance(module())) {
 289     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 290               "module is not an instance of type java.lang.Module");
 291   }
 292 
 293   int module_name_len;
 294   char* module_name = get_module_name(module(), module_name_len, CHECK);
 295   if (module_name == nullptr) {
 296     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 297               "Module name cannot be null");
 298   }
 299 
 300   // Resolve packages
 301   objArrayHandle packages_h(THREAD, objArrayOop(JNIHandles::resolve(packages)));
 302   int num_packages = (packages_h.is_null() ? 0 : packages_h->length());
 303   if (strncmp(module_name, "jdk.proxy", 9) != 0) {
 304     check_cds_restrictions(Handle(), Handle(), CHECK);
 305   }
 306 
 307   // Special handling of java.base definition
 308   if (strcmp(module_name, JAVA_BASE_NAME) == 0) {
 309     assert(is_open == JNI_FALSE, "java.base module cannot be open");
 310     define_javabase_module(module, version, location, packages_h, num_packages, CHECK);
 311     return;
 312   }
 313 
 314   oop loader = java_lang_Module::loader(module());
 315   Handle h_loader = Handle(THREAD, loader);
 316   // define_module can be called during start-up, before the class loader's ClassLoaderData
 317   // has been created.  SystemDictionary::register_loader ensures creation, if needed.
 318   ClassLoaderData* loader_data = SystemDictionary::register_loader(h_loader);
 319   assert(loader_data != nullptr, "class loader data shouldn't be null");
 320 
 321   // Only modules defined to either the boot or platform class loader, can define a "java/" package.
 322   bool java_pkg_disallowed = !h_loader.is_null() &&
 323         !SystemDictionary::is_platform_class_loader(h_loader());
 324 
 325   // Check that the list of packages has no duplicates and that the
 326   // packages are syntactically ok.
 327   char buf[128];
 328   GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);
 329   for (int x = 0; x < num_packages; x++) {
 330     oop pkg_str = packages_h->obj_at(x);
 331     if (pkg_str == nullptr || pkg_str->klass() != vmClasses::String_klass()) {
 332       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 333                 err_msg("Bad package name"));
 334     }
 335 
 336     int package_len;
 337     const char* package_name = as_internal_package(pkg_str, buf, sizeof(buf), package_len);
 338     if (!verify_package_name(package_name, package_len)) {
 339       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 340                 err_msg("Invalid package name: %s for module: %s",
 341                         package_name, module_name));
 342     }
 343 
 344     // Only modules defined to either the boot or platform class loader, can define a "java/" package.
 345     if (java_pkg_disallowed &&
 346         (strncmp(package_name, JAVAPKG, JAVAPKG_LEN) == 0 &&
 347           (package_name[JAVAPKG_LEN] == JVM_SIGNATURE_SLASH || package_name[JAVAPKG_LEN] == '\0'))) {
 348       const char* class_loader_name = loader_data->loader_name_and_id();
 349       size_t pkg_len = strlen(package_name);
 350       char* pkg_name = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, pkg_len + 1);
 351       strncpy(pkg_name, package_name, pkg_len + 1);
 352       StringUtils::replace_no_expand(pkg_name, "/", ".");
 353       const char* msg_text1 = "Class loader (instance of): ";
 354       const char* msg_text2 = " tried to define prohibited package name: ";
 355       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + pkg_len + 1;
 356       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
 357       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, pkg_name);
 358       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), message);
 359     }
 360 
 361     Symbol* pkg_symbol = SymbolTable::new_symbol(package_name, package_len);
 362     pkg_list->append(pkg_symbol);
 363   }
 364 
 365   ModuleEntryTable* module_table = get_module_entry_table(h_loader);
 366   assert(module_table != nullptr, "module entry table shouldn't be null");
 367 
 368   // Create symbol* entry for module name.
 369   TempNewSymbol module_symbol = SymbolTable::new_symbol(module_name, module_name_len);
 370 
 371   bool dupl_modules = false;
 372 
 373   // Create symbol for module version.
 374   TempNewSymbol version_symbol = as_symbol(version);
 375 
 376   // Create symbol* entry for module location.
 377   TempNewSymbol location_symbol = as_symbol(location);
 378 
 379   PackageEntryTable* package_table = nullptr;
 380   PackageEntry* existing_pkg = nullptr;
 381   {
 382     MutexLocker ml(THREAD, Module_lock);
 383 
 384     if (num_packages > 0) {
 385       package_table = get_package_entry_table(h_loader);
 386       assert(package_table != nullptr, "Missing package_table");
 387 
 388       // Check that none of the packages exist in the class loader's package table.
 389       for (int x = 0; x < pkg_list->length(); x++) {
 390         existing_pkg = package_table->locked_lookup_only(pkg_list->at(x));
 391         if (existing_pkg != nullptr) {
 392           // This could be because the module was already defined.  If so,
 393           // report that error instead of the package error.
 394           if (module_table->lookup_only(module_symbol) != nullptr) {
 395             dupl_modules = true;
 396           }
 397           break;
 398         }
 399       }
 400     }  // if (num_packages > 0)...
 401 
 402     // Add the module and its packages.
 403     if (!dupl_modules && existing_pkg == nullptr) {
 404       if (module_table->lookup_only(module_symbol) == nullptr) {
 405         // Create the entry for this module in the class loader's module entry table.
 406         ModuleEntry* module_entry = module_table->locked_create_entry(module,
 407                                     (is_open == JNI_TRUE), module_symbol,
 408                                     version_symbol, location_symbol, loader_data);
 409         assert(module_entry != nullptr, "module_entry creation failed");
 410 
 411         // Add the packages.
 412         assert(pkg_list->length() == 0 || package_table != nullptr, "Bad package table");
 413         for (int y = 0; y < pkg_list->length(); y++) {
 414           package_table->locked_create_entry(pkg_list->at(y), module_entry);
 415 
 416           // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of
 417           // the Symbol* that was created above for each package. The refcount was incremented
 418           // by SymbolTable::new_symbol and as well by the PackageEntry creation.
 419           pkg_list->at(y)->decrement_refcount();
 420         }
 421 
 422         // Store pointer to ModuleEntry record in java.lang.Module object.
 423         java_lang_Module::set_module_entry(module(), module_entry);
 424       } else {
 425          dupl_modules = true;
 426       }
 427     }
 428   }  // Release the lock
 429 
 430   // any errors ?
 431   if (dupl_modules) {
 432      THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
 433                err_msg("Module %s is already defined", module_name));
 434   } else if (existing_pkg != nullptr) {
 435       throw_dup_pkg_exception(module_name, existing_pkg, CHECK);
 436   }
 437 
 438   log_info(module, load)("%s location: %s", module_name,
 439                          location_symbol != nullptr ? location_symbol->as_C_string() : "null");
 440   LogTarget(Debug, module) lt;
 441   if (lt.is_enabled()) {
 442     LogStream ls(lt);
 443     ls.print("define_module(): creation of module: %s, version: %s, location: %s, ",
 444                  module_name, version_symbol != nullptr ? version_symbol->as_C_string() : "null",
 445                  location_symbol != nullptr ? location_symbol->as_C_string() : "null");
 446     loader_data->print_value_on(&ls);
 447     ls.print_cr(", package #: %d", pkg_list->length());
 448     for (int y = 0; y < pkg_list->length(); y++) {
 449       log_trace(module)("define_module(): creation of package %s for module %s",
 450                         (pkg_list->at(y))->as_C_string(), module_name);
 451     }
 452   }
 453 
 454   // If the module is defined to the boot loader and an exploded build is being
 455   // used, prepend <java.home>/modules/modules_name to the boot class path.
 456   if (h_loader.is_null() && !ClassLoader::has_jrt_entry()) {
 457     ClassLoader::add_to_exploded_build_list(THREAD, module_symbol);
 458   }
 459 
 460 #if COMPILER2_OR_JVMCI
 461   // Special handling of jdk.incubator.vector
 462   if (strcmp(module_name, "jdk.incubator.vector") == 0) {
 463     if (FLAG_IS_DEFAULT(EnableVectorSupport)) {
 464       FLAG_SET_DEFAULT(EnableVectorSupport, true);
 465     }
 466     if (EnableVectorSupport && FLAG_IS_DEFAULT(EnableVectorReboxing)) {
 467       FLAG_SET_DEFAULT(EnableVectorReboxing, true);
 468     }
 469     if (EnableVectorSupport && EnableVectorReboxing && FLAG_IS_DEFAULT(EnableVectorAggressiveReboxing)) {
 470       FLAG_SET_DEFAULT(EnableVectorAggressiveReboxing, true);
 471     }
 472     log_info(compilation)("EnableVectorSupport=%s",            (EnableVectorSupport            ? "true" : "false"));
 473     log_info(compilation)("EnableVectorReboxing=%s",           (EnableVectorReboxing           ? "true" : "false"));
 474     log_info(compilation)("EnableVectorAggressiveReboxing=%s", (EnableVectorAggressiveReboxing ? "true" : "false"));
 475   }
 476 #endif // COMPILER2_OR_JVMCI
 477 }
 478 
 479 #if INCLUDE_CDS_JAVA_HEAP
 480 static bool _seen_platform_unnamed_module = false;
 481 static bool _seen_system_unnamed_module = false;
 482 
 483 // Validate the states of an java.lang.Module oop to be archived.
 484 void Modules::check_archived_module_oop(oop orig_module_obj) {
 485   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
 486   assert(java_lang_Module::is_instance(orig_module_obj), "must be");
 487 
 488   ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
 489   if (orig_module_ent == nullptr) {
 490     // These special java.lang.Module oops are created in Java code. They are not
 491     // defined via Modules::define_module(), so they don't have a ModuleEntry:
 492     //     java.lang.Module::ALL_UNNAMED_MODULE
 493     //     java.lang.Module::EVERYONE_MODULE
 494     //     jdk.internal.loader.ClassLoaders$BootClassLoader::unnamedModule
 495     log_info(aot, module)("Archived java.lang.Module oop " PTR_FORMAT " with no ModuleEntry*", p2i(orig_module_obj));
 496     assert(java_lang_Module::name(orig_module_obj) == nullptr, "must be unnamed");
 497   } else {
 498     // This java.lang.Module oop has an ModuleEntry*. Check if the latter is archived.
 499     if (log_is_enabled(Info, aot, module)) {
 500       ResourceMark rm;
 501       LogStream ls(Log(aot, module)::info());
 502       ls.print("Archived java.lang.Module oop " PTR_FORMAT " for ", p2i(orig_module_obj));
 503       orig_module_ent->print(&ls);
 504     }
 505 
 506     // We only archive the default module graph, which should contain only java.lang.Module oops
 507     // for the 3 built-in loaders (boot/platform/system)
 508     ClassLoaderData* loader_data = orig_module_ent->loader_data();
 509     assert(loader_data->is_builtin_class_loader_data(), "must be");
 510 
 511     if (orig_module_ent->name() != nullptr) {
 512       // For each named module, we archive both the java.lang.Module oop and the ModuleEntry.
 513       assert(orig_module_ent->has_been_archived(), "sanity");
 514     } else {
 515       // We only archive two unnamed module oops (for platform and system loaders). These do NOT have an archived
 516       // ModuleEntry.
 517       //
 518       // At runtime, these oops are fetched from java_lang_ClassLoader::unnamedModule(loader) and
 519       // are initialized in ClassLoaderData::ClassLoaderData() => ModuleEntry::create_unnamed_module(), where
 520       // a new ModuleEntry is allocated.
 521       assert(!loader_data->is_boot_class_loader_data(), "unnamed module for boot loader should be not archived");
 522       assert(!orig_module_ent->has_been_archived(), "sanity");
 523 
 524       if (SystemDictionary::is_platform_class_loader(loader_data->class_loader())) {
 525         assert(!_seen_platform_unnamed_module, "only once");
 526         _seen_platform_unnamed_module = true;
 527       } else if (SystemDictionary::is_system_class_loader(loader_data->class_loader())) {
 528         assert(!_seen_system_unnamed_module, "only once");
 529         _seen_system_unnamed_module = true;
 530       } else {
 531         // The java.lang.Module oop and ModuleEntry of the unnamed module of the boot loader are
 532         // not in the archived module graph. These are always allocated at runtime.
 533         ShouldNotReachHere();
 534       }
 535     }
 536   }
 537 }
 538 
 539 void Modules::verify_archived_modules() {
 540   ModuleEntry::verify_archived_module_entries();
 541 }
 542 
 543 class Modules::ArchivedProperty {
 544   const char* _prop;
 545   const bool _numbered;
 546   const char* _archived_value;
 547 
 548   const char* get_flattened_value() const {
 549     if (_numbered) {
 550       return get_numbered_property_as_sorted_string();
 551     } else {
 552       return Arguments::get_property(_prop);
 553     }
 554   }
 555 
 556   void runtime_check() const;
 557   const char* get_numbered_property_as_sorted_string() const;
 558 
 559 public:
 560   ArchivedProperty(const char* prop, bool numbered)
 561     : _prop(prop), _numbered(numbered), _archived_value(nullptr) {}
 562 
 563   void dump() {
 564     ResourceMark rm;
 565     const char* str = get_flattened_value();
 566     if (str != nullptr) {
 567       _archived_value = ArchiveBuilder::current()->ro_strdup(str);
 568     }
 569   }
 570 
 571   void serialize(SerializeClosure* soc) {
 572     soc->do_ptr(&_archived_value);
 573     if (soc->reading()) {
 574       runtime_check();
 575       // Don't hold onto the pointer, in case we might decide to unmap the archive.
 576       _archived_value = nullptr;
 577     }
 578   }
 579 };
 580 
 581 Modules::ArchivedProperty Modules::_archived_props[] = {
 582   // non-numbered
 583   {"jdk.module.main", false},
 584 
 585   // numbered
 586   {"jdk.module.addexports", true},             // --add-exports
 587   {"jdk.module.addmods", true},                // --add-modules
 588   {"jdk.module.enable.native.access", true},   // --enable-native-access
 589   {"jdk.module.addopens", true},               // --add-opens
 590   {"jdk.module.addreads", true},               // --add-reads
 591 };
 592 
 593 constexpr size_t Modules::num_archived_props() {
 594   return sizeof(_archived_props) / sizeof(_archived_props[0]);
 595 }
 596 
 597 Modules::ArchivedProperty& Modules::archived_prop(size_t i) {
 598   assert(i < num_archived_props(), "oob");
 599   return _archived_props[i];
 600 }
 601 
 602 void Modules::ArchivedProperty::runtime_check() const {
 603   ResourceMark rm;
 604   const char* runtime_value = get_flattened_value();
 605   aot_log_info(aot)("archived module property %s: %s", _prop,
 606                 _archived_value != nullptr ? _archived_value : "(null)");
 607 
 608   bool disable = false;
 609   if (runtime_value == nullptr) {
 610     if (_archived_value != nullptr) {
 611       MetaspaceShared::report_loading_error("Mismatched values for property %s: %s specified during dump time but not during runtime", _prop, _archived_value);
 612       disable = true;
 613     }
 614   } else {
 615     if (_archived_value == nullptr) {
 616       MetaspaceShared::report_loading_error("Mismatched values for property %s: %s specified during runtime but not during dump time", _prop, runtime_value);
 617       disable = true;
 618     } else if (strcmp(runtime_value, _archived_value) != 0) {
 619       MetaspaceShared::report_loading_error("Mismatched values for property %s: runtime %s dump time %s", _prop, runtime_value, _archived_value);
 620       disable = true;
 621     }
 622   }
 623 
 624   if (disable) {
 625     MetaspaceShared::report_loading_error("Disabling optimized module handling");
 626     CDSConfig::stop_using_optimized_module_handling();
 627   }
 628 }
 629 
 630 // Caller needs ResourceMark
 631 const char* Modules::ArchivedProperty::get_numbered_property_as_sorted_string() const {
 632   assert(_numbered, "sanity");
 633   // theoretical string size limit for decimal int, but the following loop will end much sooner due to
 634   // OS command-line size limit.
 635   const int max_digits = 10;
 636   const int extra_symbols_count = 2; // includes '.', '\0'
 637   size_t prop_len = strlen(_prop) + max_digits + extra_symbols_count;
 638   char* prop_name = resource_allocate_bytes(prop_len);
 639   GrowableArray<const char*> list;
 640   for (unsigned int i = 0;; i++) {
 641     jio_snprintf(prop_name, prop_len, "%s.%d", _prop, i);
 642     const char* prop_value = Arguments::get_property(prop_name);
 643     if (prop_value == nullptr) {
 644       break;
 645     }
 646     char* p = ResourceArea::strdup(prop_value);
 647     while (*p == ',') p++; // skip leading commas
 648     while (*p) {
 649       char* next = strchr(p, ',');
 650       if (next == nullptr) {
 651         // no more commas, p is the last element
 652         list.append(p);
 653         break;
 654       } else {
 655         *next = 0;
 656         list.append(p);
 657         p = next + 1;
 658       }
 659     }
 660   }
 661 
 662   // Example:
 663   // --add-modules=java.compiler --add-modules=java.base,java.base,,
 664   //
 665   // list[0] = "java.compiler"
 666   // list[1] = "java.base"
 667   // list[2] = "java.base"
 668   // list[3] = ""
 669   // list[4] = ""
 670   list.sort(ClassLoaderExt::compare_module_names);
 671 
 672   const char* prefix = "";
 673   stringStream st;
 674   const char* last_string = ""; // This also filters out all empty strings
 675   for (int i = 0; i < list.length(); i++) {
 676     const char* m = list.at(i);
 677     if (strcmp(m, last_string) != 0) { // filter out duplicates
 678       st.print("%s%s", prefix, m);
 679       last_string = m;
 680       prefix = ",";
 681     }
 682   }
 683 
 684   return (st.size() > 0) ? st.as_string() : nullptr;  // Example: "java.base,java.compiler"
 685 }
 686 
 687 void Modules::dump_archived_module_info() {
 688   for (size_t i = 0; i < num_archived_props(); i++) {
 689     archived_prop(i).dump();
 690   }
 691 }
 692 
 693 void Modules::serialize_archived_module_info(SerializeClosure* soc) {
 694   for (size_t i = 0; i < num_archived_props(); i++) {
 695     archived_prop(i).serialize(soc);
 696   }
 697   if (soc->reading()) {
 698     aot_log_info(aot)("optimized module handling: %s", CDSConfig::is_using_optimized_module_handling() ? "enabled" : "disabled");
 699     aot_log_info(aot)("full module graph: %s", CDSConfig::is_using_full_module_graph() ? "enabled" : "disabled");
 700   }
 701 }
 702 
 703 void Modules::define_archived_modules(Handle h_platform_loader, Handle h_system_loader, TRAPS) {
 704   assert(CDSConfig::is_using_full_module_graph(), "must be");
 705 
 706   // We don't want the classes used by the archived full module graph to be redefined by JVMTI.
 707   // Luckily, such classes are loaded in the JVMTI "early" phase, and CDS is disabled if a JVMTI
 708   // agent wants to redefine classes in this phase.
 709   JVMTI_ONLY(assert(JvmtiExport::is_early_phase(), "must be"));
 710   assert(!(JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()),
 711          "CDS should be disabled if early class hooks are enabled");
 712 
 713   Handle java_base_module(THREAD, ClassLoaderDataShared::restore_archived_oops_for_null_class_loader_data());
 714   // Patch any previously loaded class's module field with java.base's java.lang.Module.
 715   ModuleEntryTable::patch_javabase_entries(THREAD, java_base_module);
 716 
 717   if (h_platform_loader.is_null()) {
 718     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null platform loader object");
 719   }
 720 
 721   if (h_system_loader.is_null()) {
 722     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null system loader object");
 723   }
 724 
 725   ClassLoaderData* platform_loader_data = SystemDictionary::register_loader(h_platform_loader);
 726   SystemDictionary::set_platform_loader(platform_loader_data);
 727   ClassLoaderDataShared::restore_java_platform_loader_from_archive(platform_loader_data);
 728 
 729   ClassLoaderData* system_loader_data = SystemDictionary::register_loader(h_system_loader);
 730   SystemDictionary::set_system_loader(system_loader_data);
 731   // system_loader_data here is always an instance of jdk.internal.loader.ClassLoader$AppClassLoader.
 732   // However, if -Djava.system.class.loader=xxx is specified, java_platform_loader() would
 733   // be an instance of a user-defined class, so make sure this never happens.
 734   assert(Arguments::get_property("java.system.class.loader") == nullptr,
 735            "archived full module should have been disabled if -Djava.system.class.loader is specified");
 736   ClassLoaderDataShared::restore_java_system_loader_from_archive(system_loader_data);
 737 }
 738 
 739 void Modules::check_cds_restrictions(Handle module1, Handle module2, TRAPS) {
 740   if (CDSConfig::is_dumping_full_module_graph() && Universe::is_module_initialized()) {
 741     if (CDSConfig::is_dumping_dynamic_proxies() && (is_dynamic_proxy_module(module1) || is_dynamic_proxy_module(module2))) {
 742       // The only the we allow is to add or modify the jdk.proxy?? modules that are used for dynamic proxies.
 743     } else {
 744       THROW_MSG(vmSymbols::java_lang_UnsupportedOperationException(),
 745                 "During -Xshare:dump, module system cannot be modified after it's initialized");
 746     }
 747   }
 748 }
 749 
 750 #endif // INCLUDE_CDS_JAVA_HEAP
 751 
 752 bool Modules::is_dynamic_proxy_module(Handle module) {
 753   if (!module.is_null()) {
 754     ModuleEntry* module_entry = java_lang_Module::module_entry(module());
 755     return is_dynamic_proxy_module(module_entry);
 756   }
 757   return false;
 758 }
 759 
 760 bool Modules::is_dynamic_proxy_module(ModuleEntry* module_entry) {
 761   return (module_entry != nullptr && module_entry->is_named() && module_entry->name()->starts_with("jdk.proxy"));
 762 }
 763 
 764 void Modules::set_bootloader_unnamed_module(Handle module, TRAPS) {
 765   ResourceMark rm(THREAD);
 766 
 767   if (module.is_null()) {
 768     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
 769   }
 770   if (!java_lang_Module::is_instance(module())) {
 771     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 772               "module is not an instance of type java.lang.Module");
 773   }
 774 
 775   // Ensure that this is an unnamed module
 776   oop name = java_lang_Module::name(module());
 777   if (name != nullptr) {
 778     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 779               "boot loader's unnamed module's java.lang.Module has a name");
 780   }
 781 
 782   // Validate java_base's loader is the boot loader.
 783   oop loader = java_lang_Module::loader(module());
 784   if (loader != nullptr) {
 785     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 786               "Class loader must be the boot class loader");
 787   }
 788 
 789   log_debug(module)("set_bootloader_unnamed_module(): recording unnamed module for boot loader");
 790 
 791   // Set java.lang.Module for the boot loader's unnamed module
 792   ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
 793   ModuleEntry* unnamed_module = boot_loader_data->unnamed_module();
 794   assert(unnamed_module != nullptr, "boot loader's unnamed ModuleEntry not defined");
 795   unnamed_module->set_module(boot_loader_data->add_handle(module));
 796   // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
 797   java_lang_Module::set_module_entry(module(), unnamed_module);
 798 }
 799 
 800 void Modules::add_module_exports(Handle from_module, jstring package_name, Handle to_module, TRAPS) {
 801   check_cds_restrictions(from_module, to_module, CHECK);
 802 
 803   if (package_name == nullptr) {
 804     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 805               "package is null");
 806   }
 807   if (from_module.is_null()) {
 808     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 809               "from_module is null");
 810   }
 811   ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
 812   if (from_module_entry == nullptr) {
 813     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 814               "from_module cannot be found");
 815   }
 816 
 817   // All packages in unnamed and open modules are exported by default.
 818   if (!from_module_entry->is_named() || from_module_entry->is_open()) return;
 819 
 820   ModuleEntry* to_module_entry;
 821   if (to_module.is_null()) {
 822     to_module_entry = nullptr;  // It's an unqualified export.
 823   } else {
 824     to_module_entry = get_module_entry(to_module, CHECK);
 825     if (to_module_entry == nullptr) {
 826       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 827                 "to_module is invalid");
 828     }
 829   }
 830 
 831   PackageEntry* package_entry = nullptr;
 832   char buf[128];
 833   int package_len;
 834 
 835   ResourceMark rm(THREAD);
 836   const char* pkg = as_internal_package(JNIHandles::resolve_non_null(package_name), buf, sizeof(buf), package_len);
 837   {
 838     MutexLocker ml(THREAD, Module_lock);
 839     package_entry = get_locked_package_entry(from_module_entry, pkg, package_len);
 840     // Do nothing if modules are the same
 841     // If the package is not found we'll throw an exception later
 842     if (from_module_entry != to_module_entry &&
 843         package_entry != nullptr) {
 844       package_entry->set_exported(to_module_entry);
 845     }
 846   }
 847 
 848   // Handle errors and logging outside locked section
 849   if (package_entry == nullptr) {
 850     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 851               err_msg("Package %s not found in from_module %s",
 852                       pkg != nullptr ? pkg : "",
 853                       from_module_entry->name()->as_C_string()));
 854   }
 855 
 856   if (log_is_enabled(Debug, module)) {
 857     log_debug(module)("add_module_exports(): package %s in module %s is exported to module %s",
 858                       package_entry->name()->as_C_string(),
 859                       from_module_entry->name()->as_C_string(),
 860                       to_module_entry == nullptr ? "null" :
 861                       to_module_entry->is_named() ?
 862                       to_module_entry->name()->as_C_string() : UNNAMED_MODULE);
 863   }
 864 }
 865 
 866 
 867 void Modules::add_module_exports_qualified(Handle from_module, jstring package,
 868                                            Handle to_module, TRAPS) {
 869   check_cds_restrictions(from_module, to_module, CHECK);
 870   if (to_module.is_null()) {
 871     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 872               "to_module is null");
 873   }
 874   add_module_exports(from_module, package, to_module, CHECK);
 875 }
 876 
 877 void Modules::add_reads_module(Handle from_module, Handle to_module, TRAPS) {
 878   check_cds_restrictions(from_module, to_module, CHECK);
 879   if (from_module.is_null()) {
 880     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 881               "from_module is null");
 882   }
 883 
 884   ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
 885   if (from_module_entry == nullptr) {
 886     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 887               "from_module is not valid");
 888   }
 889 
 890   ModuleEntry* to_module_entry;
 891   if (!to_module.is_null()) {
 892     to_module_entry = get_module_entry(to_module, CHECK);
 893     if (to_module_entry == nullptr) {
 894       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 895                 "to_module is invalid");
 896     }
 897   } else {
 898     to_module_entry = nullptr;
 899   }
 900 
 901   ResourceMark rm(THREAD);
 902   log_debug(module)("add_reads_module(): Adding read from module %s to module %s",
 903                     from_module_entry->is_named() ?
 904                     from_module_entry->name()->as_C_string() : UNNAMED_MODULE,
 905                     to_module_entry == nullptr ? "all unnamed" :
 906                       (to_module_entry->is_named() ?
 907                        to_module_entry->name()->as_C_string() : UNNAMED_MODULE));
 908 
 909   // if modules are the same or if from_module is unnamed then no need to add the read.
 910   if (from_module_entry != to_module_entry && from_module_entry->is_named()) {
 911     from_module_entry->add_read(to_module_entry);
 912   }
 913 }
 914 
 915 // This method is called by JFR and JNI.
 916 jobject Modules::get_module(jclass clazz, TRAPS) {
 917   assert(ModuleEntryTable::javabase_defined(),
 918          "Attempt to call get_module before " JAVA_BASE_NAME " is defined");
 919 
 920   if (clazz == nullptr) {
 921     THROW_MSG_(vmSymbols::java_lang_NullPointerException(),
 922                "class is null", nullptr);
 923   }
 924   oop mirror = JNIHandles::resolve_non_null(clazz);
 925   if (mirror == nullptr) {
 926     log_debug(module)("get_module(): no mirror, returning nullptr");
 927     return nullptr;
 928   }
 929   if (!java_lang_Class::is_instance(mirror)) {
 930     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
 931                "Invalid class", nullptr);
 932   }
 933 
 934   oop module = java_lang_Class::module(mirror);
 935 
 936   assert(module != nullptr, "java.lang.Class module field not set");
 937   assert(java_lang_Module::is_instance(module), "module is not an instance of type java.lang.Module");
 938 
 939   LogTarget(Debug,module) lt;
 940   if (lt.is_enabled()) {
 941     LogStream ls(lt);
 942     Klass* klass = java_lang_Class::as_Klass(mirror);
 943     oop module_name = java_lang_Module::name(module);
 944     if (module_name != nullptr) {
 945       ls.print("get_module(): module ");
 946       java_lang_String::print(module_name, tty);
 947     } else {
 948       ls.print("get_module(): Unnamed Module");
 949     }
 950     if (klass != nullptr) {
 951       ResourceMark rm(THREAD);
 952       ls.print_cr(" for class %s", klass->external_name());
 953     } else {
 954       ls.print_cr(" for primitive class");
 955     }
 956   }
 957 
 958   return JNIHandles::make_local(THREAD, module);
 959 }
 960 
 961 oop Modules::get_named_module(Handle h_loader, const char* package_name) {
 962   assert(ModuleEntryTable::javabase_defined(),
 963          "Attempt to call get_named_module before " JAVA_BASE_NAME " is defined");
 964   assert(h_loader.is_null() || java_lang_ClassLoader::is_subclass(h_loader->klass()),
 965          "Class loader is not a subclass of java.lang.ClassLoader");
 966   assert(package_name != nullptr, "the package_name should not be null");
 967 
 968   if (strlen(package_name) == 0) {
 969     return nullptr;
 970   }
 971   TempNewSymbol package_sym = SymbolTable::new_symbol(package_name);
 972   const PackageEntry* const pkg_entry =
 973     get_package_entry_by_name(package_sym, h_loader);
 974   const ModuleEntry* const module_entry = (pkg_entry != nullptr ? pkg_entry->module() : nullptr);
 975 
 976   if (module_entry != nullptr && module_entry->module() != nullptr && module_entry->is_named()) {
 977     return module_entry->module();
 978   }
 979   return nullptr;
 980 }
 981 
 982 // Export package in module to all unnamed modules.
 983 void Modules::add_module_exports_to_all_unnamed(Handle module, jstring package_name, TRAPS) {
 984   check_cds_restrictions(Handle(), module, CHECK);
 985   if (module.is_null()) {
 986     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 987               "module is null");
 988   }
 989   if (package_name == nullptr) {
 990     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 991               "package is null");
 992   }
 993   ModuleEntry* module_entry = get_module_entry(module, CHECK);
 994   if (module_entry == nullptr) {
 995     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 996               "module is invalid");
 997   }
 998 
 999   // No-op for unnamed module and open modules
1000   if (!module_entry->is_named() || module_entry->is_open())
1001     return;
1002 
1003   ResourceMark rm(THREAD);
1004   char buf[128];
1005   int pkg_len;
1006   const char* pkg = as_internal_package(JNIHandles::resolve_non_null(package_name), buf, sizeof(buf), pkg_len);
1007   PackageEntry* package_entry = nullptr;
1008   {
1009     MutexLocker m1(THREAD, Module_lock);
1010     package_entry = get_locked_package_entry(module_entry, pkg, pkg_len);
1011 
1012     // Mark package as exported to all unnamed modules.
1013     if (package_entry != nullptr) {
1014       package_entry->set_is_exported_allUnnamed();
1015     }
1016   }
1017 
1018   // Handle errors and logging outside locked section
1019   if (package_entry == nullptr) {
1020     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
1021               err_msg("Package %s not found in module %s",
1022                       pkg != nullptr ? pkg : "",
1023                       module_entry->name()->as_C_string()));
1024   }
1025 
1026   if (log_is_enabled(Debug, module)) {
1027     log_debug(module)("add_module_exports_to_all_unnamed(): package %s in module"
1028                       " %s is exported to all unnamed modules",
1029                        package_entry->name()->as_C_string(),
1030                        module_entry->name()->as_C_string());
1031   }
1032 }