1 /*
  2 * Copyright (c) 2016, 2024, 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 "precompiled.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/javaAssertions.hpp"
 34 #include "classfile/javaClasses.hpp"
 35 #include "classfile/javaClasses.inline.hpp"
 36 #include "classfile/moduleEntry.hpp"
 37 #include "classfile/modules.hpp"
 38 #include "classfile/packageEntry.hpp"
 39 #include "classfile/stringTable.hpp"
 40 #include "classfile/symbolTable.hpp"
 41 #include "classfile/systemDictionary.hpp"
 42 #include "classfile/vmClasses.hpp"
 43 #include "classfile/vmSymbols.hpp"
 44 #include "jvm.h"
 45 #include "logging/log.hpp"
 46 #include "logging/logStream.hpp"
 47 #include "memory/resourceArea.hpp"
 48 #include "prims/jvmtiExport.hpp"
 49 #include "runtime/arguments.hpp"
 50 #include "runtime/globals_extension.hpp"
 51 #include "runtime/handles.inline.hpp"
 52 #include "runtime/javaCalls.hpp"
 53 #include "runtime/jniHandles.inline.hpp"
 54 #include "utilities/formatBuffer.hpp"
 55 #include "utilities/stringUtils.hpp"
 56 #include "utilities/utf8.hpp"
 57 
 58 static bool verify_module_name(const char *module_name, int len) {
 59   assert(module_name != nullptr, "invariant");
 60   return (len > 0 && len <= Symbol::max_length());
 61 }
 62 
 63 static bool verify_package_name(const char* package_name, int len) {
 64   assert(package_name != nullptr, "Package name derived from non-null jstring can't be null");
 65   return (len > 0 && len <= Symbol::max_length() &&
 66     ClassFileParser::verify_unqualified_name(package_name, len,
 67     ClassFileParser::LegalClass));
 68 }
 69 
 70 static char* get_module_name(oop module, int& len, TRAPS) {
 71   oop name_oop = java_lang_Module::name(module);
 72   if (name_oop == nullptr) {
 73     THROW_MSG_NULL(vmSymbols::java_lang_NullPointerException(), "Null module name");
 74   }
 75   size_t utf8_len;
 76   char* module_name = java_lang_String::as_utf8_string(name_oop, utf8_len);
 77   len = checked_cast<int>(utf8_len); // module names are < 64K
 78   if (!verify_module_name(module_name, len)) {
 79     THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),
 80                    err_msg("Invalid module name: %s", module_name));
 81   }
 82   return module_name;
 83 }
 84 
 85 static Symbol* as_symbol(jstring str_object) {
 86   if (str_object == nullptr) {
 87     return nullptr;
 88   }
 89   size_t len;
 90   char* str = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(str_object), len);
 91   return SymbolTable::new_symbol(str, checked_cast<int>(len));
 92 }
 93 
 94 ModuleEntryTable* Modules::get_module_entry_table(Handle h_loader) {
 95   // This code can be called during start-up, before the classLoader's classLoader data got
 96   // created.  So, call register_loader() to make sure the classLoader data gets created.
 97   ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader);
 98   return loader_cld->modules();
 99 }
100 
101 static PackageEntryTable* get_package_entry_table(Handle h_loader) {
102   // This code can be called during start-up, before the classLoader's classLoader data got
103   // created.  So, call register_loader() to make sure the classLoader data gets created.
104   ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader);
105   return loader_cld->packages();
106 }
107 
108 static ModuleEntry* get_module_entry(Handle module, TRAPS) {
109   if (!java_lang_Module::is_instance(module())) {
110     THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),
111                    "module is not an instance of type java.lang.Module");
112   }
113   return java_lang_Module::module_entry(module());
114 }
115 
116 
117 static PackageEntry* get_locked_package_entry(ModuleEntry* module_entry, const char* package_name, int len) {
118   assert(Module_lock->owned_by_self(), "should have the Module_lock");
119   assert(package_name != nullptr, "Precondition");
120   TempNewSymbol pkg_symbol = SymbolTable::new_symbol(package_name, len);
121   PackageEntryTable* package_entry_table = module_entry->loader_data()->packages();
122   assert(package_entry_table != nullptr, "Unexpected null package entry table");
123   PackageEntry* package_entry = package_entry_table->locked_lookup_only(pkg_symbol);
124   assert(package_entry == nullptr || package_entry->module() == module_entry, "Unexpectedly found a package linked to another module");
125   return package_entry;
126 }
127 
128 static PackageEntry* get_package_entry_by_name(Symbol* package, Handle h_loader) {
129   if (package != nullptr) {
130     PackageEntryTable* const package_entry_table =
131       get_package_entry_table(h_loader);
132     assert(package_entry_table != nullptr, "Unexpected null package entry table");
133     return package_entry_table->lookup_only(package);
134   }
135   return nullptr;
136 }
137 
138 bool Modules::is_package_defined(Symbol* package, Handle h_loader) {
139   PackageEntry* res = get_package_entry_by_name(package, h_loader);
140   return res != nullptr;
141 }
142 
143 // Converts the String oop to an internal package
144 // Will use the provided buffer if it's sufficiently large, otherwise allocates
145 // a resource array
146 // The length of the resulting string will be assigned to utf8_len
147 static const char* as_internal_package(oop package_string, char* buf, size_t buflen, int& utf8_len) {
148   size_t full_utf8_len;
149   char* package_name = java_lang_String::as_utf8_string_full(package_string, buf, buflen, full_utf8_len);
150   utf8_len = checked_cast<int>(full_utf8_len); // package names are < 64K
151 
152   // Turn all '/'s into '.'s
153   for (int index = 0; index < utf8_len; index++) {
154     if (package_name[index] == JVM_SIGNATURE_DOT) {
155       package_name[index] = JVM_SIGNATURE_SLASH;
156     }
157   }
158   return package_name;
159 }
160 
161 static void define_javabase_module(Handle module_handle, jstring version, jstring location,
162                                    objArrayHandle pkgs, int num_packages, TRAPS) {
163   ResourceMark rm(THREAD);
164 
165   // Obtain java.base's module version
166   TempNewSymbol version_symbol = as_symbol(version);
167 
168   // Obtain java.base's location
169   TempNewSymbol location_symbol = as_symbol(location);
170 
171   // Check that the packages are syntactically ok.
172   char buf[128];
173   GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);
174   for (int x = 0; x < num_packages; x++) {
175     oop pkg_str = pkgs->obj_at(x);
176 
177     if (pkg_str == nullptr || pkg_str->klass() != vmClasses::String_klass()) {
178       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
179                 err_msg("Bad package name"));
180     }
181 
182     int package_len;
183     const char* package_name = as_internal_package(pkg_str, buf, sizeof(buf), package_len);
184     if (!verify_package_name(package_name, package_len)) {
185       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
186                 err_msg("Invalid package name: %s for module: " JAVA_BASE_NAME, package_name));
187     }
188     Symbol* pkg_symbol = SymbolTable::new_symbol(package_name, package_len);
189     pkg_list->append(pkg_symbol);
190   }
191 
192   // Validate java_base's loader is the boot loader.
193   oop loader = java_lang_Module::loader(module_handle());
194   if (loader != nullptr) {
195     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
196               "Class loader must be the boot class loader");
197   }
198   Handle h_loader(THREAD, loader);
199 
200   // Ensure the boot loader's PackageEntryTable has been created
201   PackageEntryTable* package_table = get_package_entry_table(h_loader);
202   assert(pkg_list->length() == 0 || package_table != nullptr, "Bad package_table");
203 
204   // Ensure java.base's ModuleEntry has been created
205   assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, "No ModuleEntry for " JAVA_BASE_NAME);
206 
207   bool duplicate_javabase = false;
208   {
209     MutexLocker m1(THREAD, Module_lock);
210 
211     if (ModuleEntryTable::javabase_defined()) {
212       duplicate_javabase = true;
213     } else {
214 
215       // Verify that all java.base packages created during bootstrapping are in
216       // pkg_list.  If any are not in pkg_list, than a non-java.base class was
217       // loaded erroneously pre java.base module definition.
218       package_table->verify_javabase_packages(pkg_list);
219 
220       // loop through and add any new packages for java.base
221       for (int x = 0; x < pkg_list->length(); x++) {
222         // Some of java.base's packages were added early in bootstrapping, ignore duplicates.
223         package_table->locked_create_entry_if_absent(pkg_list->at(x),
224                                                      ModuleEntryTable::javabase_moduleEntry());
225         assert(package_table->locked_lookup_only(pkg_list->at(x)) != nullptr,
226                "Unable to create a " JAVA_BASE_NAME " package entry");
227         // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of
228         // the Symbol* that was created above for each package. The refcount was incremented
229         // by SymbolTable::new_symbol and as well by the PackageEntry creation.
230         pkg_list->at(x)->decrement_refcount();
231       }
232 
233       // Finish defining java.base's ModuleEntry
234       ModuleEntryTable::finalize_javabase(module_handle, version_symbol, location_symbol);
235     }
236   }
237   if (duplicate_javabase) {
238     THROW_MSG(vmSymbols::java_lang_InternalError(),
239               "Module " JAVA_BASE_NAME " is already defined");
240   }
241 
242   // Only the thread that actually defined the base module will get here,
243   // so no locking is needed.
244 
245   // Patch any previously loaded class's module field with java.base's java.lang.Module.
246   ModuleEntryTable::patch_javabase_entries(THREAD, module_handle);
247 
248   log_info(module, load)(JAVA_BASE_NAME " location: %s",
249                          location_symbol != nullptr ? location_symbol->as_C_string() : "nullptr");
250   log_debug(module)("define_javabase_module(): Definition of module: "
251                     JAVA_BASE_NAME ", version: %s, location: %s, package #: %d",
252                     version_symbol != nullptr ? version_symbol->as_C_string() : "nullptr",
253                     location_symbol != nullptr ? location_symbol->as_C_string() : "nullptr",
254                     pkg_list->length());
255 
256   // packages defined to java.base
257   if (log_is_enabled(Trace, module)) {
258     for (int x = 0; x < pkg_list->length(); x++) {
259       log_trace(module)("define_javabase_module(): creation of package %s for module " JAVA_BASE_NAME,
260                         (pkg_list->at(x))->as_C_string());
261     }
262   }
263 }
264 
265 // Caller needs ResourceMark.
266 static void throw_dup_pkg_exception(const char* module_name, PackageEntry* package, TRAPS) {
267   const char* package_name = package->name()->as_C_string();
268   if (package->module()->is_named()) {
269     THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
270       err_msg("Package %s for module %s is already in another module, %s, defined to the class loader",
271               package_name, module_name, package->module()->name()->as_C_string()));
272   } else {
273     THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
274       err_msg("Package %s for module %s is already in the unnamed module defined to the class loader",
275               package_name, module_name));
276   }
277 }
278 
279 void Modules::define_module(Handle module, jboolean is_open, jstring version,
280                             jstring location, jobjectArray packages, TRAPS) {

281   ResourceMark rm(THREAD);
282 
283   if (module.is_null()) {
284     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
285   }
286 
287   if (!java_lang_Module::is_instance(module())) {
288     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
289               "module is not an instance of type java.lang.Module");
290   }
291 
292   int module_name_len;
293   char* module_name = get_module_name(module(), module_name_len, CHECK);
294   if (module_name == nullptr) {
295     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
296               "Module name cannot be null");
297   }
298 
299   // Resolve packages
300   objArrayHandle packages_h(THREAD, objArrayOop(JNIHandles::resolve(packages)));
301   int num_packages = (packages_h.is_null() ? 0 : packages_h->length());
302   if (strncmp(module_name, "jdk.proxy", 9) != 0) {
303     check_cds_restrictions(Handle(), Handle(), CHECK);
304   }
305 
306   // Special handling of java.base definition
307   if (strcmp(module_name, JAVA_BASE_NAME) == 0) {
308     assert(is_open == JNI_FALSE, "java.base module cannot be open");
309     define_javabase_module(module, version, location, packages_h, num_packages, CHECK);
310     return;
311   }
312 
313   oop loader = java_lang_Module::loader(module());
314   // Make sure loader is not the jdk.internal.reflect.DelegatingClassLoader.
315   if (loader != java_lang_ClassLoader::non_reflection_class_loader(loader)) {
316     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
317               "Class loader is an invalid delegating class loader");
318   }
319   Handle h_loader = Handle(THREAD, loader);
320   // define_module can be called during start-up, before the class loader's ClassLoaderData
321   // has been created.  SystemDictionary::register_loader ensures creation, if needed.
322   ClassLoaderData* loader_data = SystemDictionary::register_loader(h_loader);
323   assert(loader_data != nullptr, "class loader data shouldn't be null");
324 
325   // Only modules defined to either the boot or platform class loader, can define a "java/" package.
326   bool java_pkg_disallowed = !h_loader.is_null() &&
327         !SystemDictionary::is_platform_class_loader(h_loader());
328 
329   // Check that the list of packages has no duplicates and that the
330   // packages are syntactically ok.
331   char buf[128];
332   GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);
333   for (int x = 0; x < num_packages; x++) {
334     oop pkg_str = packages_h->obj_at(x);
335     if (pkg_str == nullptr || pkg_str->klass() != vmClasses::String_klass()) {
336       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
337                 err_msg("Bad package name"));
338     }
339 
340     int package_len;
341     const char* package_name = as_internal_package(pkg_str, buf, sizeof(buf), package_len);
342     if (!verify_package_name(package_name, package_len)) {
343       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
344                 err_msg("Invalid package name: %s for module: %s",
345                         package_name, module_name));
346     }
347 
348     // Only modules defined to either the boot or platform class loader, can define a "java/" package.
349     if (java_pkg_disallowed &&
350         (strncmp(package_name, JAVAPKG, JAVAPKG_LEN) == 0 &&
351           (package_name[JAVAPKG_LEN] == JVM_SIGNATURE_SLASH || package_name[JAVAPKG_LEN] == '\0'))) {
352       const char* class_loader_name = loader_data->loader_name_and_id();
353       size_t pkg_len = strlen(package_name);
354       char* pkg_name = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, pkg_len + 1);
355       strncpy(pkg_name, package_name, pkg_len + 1);
356       StringUtils::replace_no_expand(pkg_name, "/", ".");
357       const char* msg_text1 = "Class loader (instance of): ";
358       const char* msg_text2 = " tried to define prohibited package name: ";
359       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + pkg_len + 1;
360       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
361       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, pkg_name);
362       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), message);
363     }
364 
365     Symbol* pkg_symbol = SymbolTable::new_symbol(package_name, package_len);
366     pkg_list->append(pkg_symbol);
367   }
368 
369   ModuleEntryTable* module_table = get_module_entry_table(h_loader);
370   assert(module_table != nullptr, "module entry table shouldn't be null");
371 
372   // Create symbol* entry for module name.
373   TempNewSymbol module_symbol = SymbolTable::new_symbol(module_name, module_name_len);
374 
375   bool dupl_modules = false;
376 
377   // Create symbol for module version.
378   TempNewSymbol version_symbol = as_symbol(version);
379 
380   // Create symbol* entry for module location.
381   TempNewSymbol location_symbol = as_symbol(location);
382 
383   PackageEntryTable* package_table = nullptr;
384   PackageEntry* existing_pkg = nullptr;
385   {
386     MutexLocker ml(THREAD, Module_lock);
387 
388     if (num_packages > 0) {
389       package_table = get_package_entry_table(h_loader);
390       assert(package_table != nullptr, "Missing package_table");
391 
392       // Check that none of the packages exist in the class loader's package table.
393       for (int x = 0; x < pkg_list->length(); x++) {
394         existing_pkg = package_table->locked_lookup_only(pkg_list->at(x));
395         if (existing_pkg != nullptr) {
396           // This could be because the module was already defined.  If so,
397           // report that error instead of the package error.
398           if (module_table->lookup_only(module_symbol) != nullptr) {
399             dupl_modules = true;
400           }
401           break;
402         }
403       }
404     }  // if (num_packages > 0)...
405 
406     // Add the module and its packages.
407     if (!dupl_modules && existing_pkg == nullptr) {
408       if (module_table->lookup_only(module_symbol) == nullptr) {
409         // Create the entry for this module in the class loader's module entry table.
410         ModuleEntry* module_entry = module_table->locked_create_entry(module,
411                                     (is_open == JNI_TRUE), module_symbol,
412                                     version_symbol, location_symbol, loader_data);
413         assert(module_entry != nullptr, "module_entry creation failed");
414 
415         // Add the packages.
416         assert(pkg_list->length() == 0 || package_table != nullptr, "Bad package table");
417         for (int y = 0; y < pkg_list->length(); y++) {
418           package_table->locked_create_entry(pkg_list->at(y), module_entry);
419 
420           // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of
421           // the Symbol* that was created above for each package. The refcount was incremented
422           // by SymbolTable::new_symbol and as well by the PackageEntry creation.
423           pkg_list->at(y)->decrement_refcount();
424         }
425 
426         // Store pointer to ModuleEntry record in java.lang.Module object.
427         java_lang_Module::set_module_entry(module(), module_entry);
428       } else {
429          dupl_modules = true;
430       }
431     }
432   }  // Release the lock
433 
434   // any errors ?
435   if (dupl_modules) {
436      THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
437                err_msg("Module %s is already defined", module_name));
438   } else if (existing_pkg != nullptr) {
439       throw_dup_pkg_exception(module_name, existing_pkg, CHECK);
440   }
441 
442   log_info(module, load)("%s location: %s", module_name,
443                          location_symbol != nullptr ? location_symbol->as_C_string() : "null");
444   LogTarget(Debug, module) lt;
445   if (lt.is_enabled()) {
446     LogStream ls(lt);
447     ls.print("define_module(): creation of module: %s, version: %s, location: %s, ",
448                  module_name, version_symbol != nullptr ? version_symbol->as_C_string() : "null",
449                  location_symbol != nullptr ? location_symbol->as_C_string() : "null");
450     loader_data->print_value_on(&ls);
451     ls.print_cr(", package #: %d", pkg_list->length());
452     for (int y = 0; y < pkg_list->length(); y++) {
453       log_trace(module)("define_module(): creation of package %s for module %s",
454                         (pkg_list->at(y))->as_C_string(), module_name);
455     }
456   }
457 
458   // If the module is defined to the boot loader and an exploded build is being
459   // used, prepend <java.home>/modules/modules_name to the boot class path.
460   if (h_loader.is_null() && !ClassLoader::has_jrt_entry()) {
461     ClassLoader::add_to_exploded_build_list(THREAD, module_symbol);
462   }
463 
464 #if COMPILER2_OR_JVMCI
465   // Special handling of jdk.incubator.vector
466   if (strcmp(module_name, "jdk.incubator.vector") == 0) {
467     if (FLAG_IS_DEFAULT(EnableVectorSupport)) {
468       FLAG_SET_DEFAULT(EnableVectorSupport, true);
469     }
470     if (EnableVectorSupport && FLAG_IS_DEFAULT(EnableVectorReboxing)) {
471       FLAG_SET_DEFAULT(EnableVectorReboxing, true);
472     }
473     if (EnableVectorSupport && EnableVectorReboxing && FLAG_IS_DEFAULT(EnableVectorAggressiveReboxing)) {
474       FLAG_SET_DEFAULT(EnableVectorAggressiveReboxing, true);
475     }
476     if (EnableVectorSupport && FLAG_IS_DEFAULT(UseVectorStubs)) {
477       FLAG_SET_DEFAULT(UseVectorStubs, true);
478     }
479     log_info(compilation)("EnableVectorSupport=%s",            (EnableVectorSupport            ? "true" : "false"));
480     log_info(compilation)("EnableVectorReboxing=%s",           (EnableVectorReboxing           ? "true" : "false"));
481     log_info(compilation)("EnableVectorAggressiveReboxing=%s", (EnableVectorAggressiveReboxing ? "true" : "false"));
482     log_info(compilation)("UseVectorStubs=%s",                 (UseVectorStubs                 ? "true" : "false"));
483   }
484 #endif // COMPILER2_OR_JVMCI
485 }
486 
487 #if INCLUDE_CDS_JAVA_HEAP
488 static bool _seen_platform_unnamed_module = false;
489 static bool _seen_system_unnamed_module = false;
490 
491 // Validate the states of an java.lang.Module oop to be archived.
492 //
493 // Returns true iff the oop has an archived ModuleEntry.
494 bool Modules::check_archived_module_oop(oop orig_module_obj) {
495   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
496   assert(java_lang_Module::is_instance(orig_module_obj), "must be");
497 
498   ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
499   if (orig_module_ent == nullptr) {
500     // These special java.lang.Module oops are created in Java code. They are not
501     // defined via Modules::define_module(), so they don't have a ModuleEntry:
502     //     java.lang.Module::ALL_UNNAMED_MODULE
503     //     java.lang.Module::EVERYONE_MODULE
504     //     jdk.internal.loader.ClassLoaders$BootClassLoader::unnamedModule
505     log_info(cds, module)("Archived java.lang.Module oop " PTR_FORMAT " with no ModuleEntry*", p2i(orig_module_obj));
506     assert(java_lang_Module::name(orig_module_obj) == nullptr, "must be unnamed");
507     return false;
508   } else {
509     // This java.lang.Module oop has an ModuleEntry*. Check if the latter is archived.
510     if (log_is_enabled(Info, cds, module)) {
511       ResourceMark rm;
512       LogStream ls(Log(cds, module)::info());
513       ls.print("Archived java.lang.Module oop " PTR_FORMAT " for ", p2i(orig_module_obj));
514       orig_module_ent->print(&ls);
515     }
516 
517     // We only archive the default module graph, which should contain only java.lang.Module oops
518     // for the 3 built-in loaders (boot/platform/system)
519     ClassLoaderData* loader_data = orig_module_ent->loader_data();
520     assert(loader_data->is_builtin_class_loader_data(), "must be");
521 
522     if (orig_module_ent->name() != nullptr) {
523       // For each named module, we archive both the java.lang.Module oop and the ModuleEntry.
524       assert(orig_module_ent->has_been_archived(), "sanity");
525       return true;
526     } else {
527       // We only archive two unnamed module oops (for platform and system loaders). These do NOT have an archived
528       // ModuleEntry.
529       //
530       // At runtime, these oops are fetched from java_lang_ClassLoader::unnamedModule(loader) and
531       // are initialized in ClassLoaderData::ClassLoaderData() => ModuleEntry::create_unnamed_module(), where
532       // a new ModuleEntry is allocated.
533       assert(!loader_data->is_boot_class_loader_data(), "unnamed module for boot loader should be not archived");
534       assert(!orig_module_ent->has_been_archived(), "sanity");
535 
536       if (SystemDictionary::is_platform_class_loader(loader_data->class_loader())) {
537         assert(!_seen_platform_unnamed_module, "only once");
538         _seen_platform_unnamed_module = true;
539       } else if (SystemDictionary::is_system_class_loader(loader_data->class_loader())) {
540         assert(!_seen_system_unnamed_module, "only once");
541         _seen_system_unnamed_module = true;
542       } else {
543         // The java.lang.Module oop and ModuleEntry of the unnamed module of the boot loader are
544         // not in the archived module graph. These are always allocated at runtime.
545         ShouldNotReachHere();
546       }
547       return false;
548     }
549   }
550 }
551 
552 void Modules::update_oops_in_archived_module(oop orig_module_obj, int archived_module_root_index) {
553   // This java.lang.Module oop must have an archived ModuleEntry
554   assert(check_archived_module_oop(orig_module_obj) == true, "sanity");
555 
556   // We remember the oop inside the ModuleEntry::_archived_module_index. At runtime, we use
557   // this index to reinitialize the ModuleEntry inside ModuleEntry::restore_archived_oops().
558   //
559   // ModuleEntry::verify_archived_module_entries(), called below, ensures that every archived
560   // ModuleEntry has been assigned an _archived_module_index.
561   ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
562   ModuleEntry::get_archived_entry(orig_module_ent)->update_oops_in_archived_module(archived_module_root_index);
563 }
564 
565 void Modules::verify_archived_modules() {
566   ModuleEntry::verify_archived_module_entries();
567 }
568 
569 char* Modules::_archived_main_module_name = nullptr;
570 
571 void Modules::dump_main_module_name() {
572   const char* module_name = Arguments::get_property("jdk.module.main");
573   if (module_name != nullptr) {
574     _archived_main_module_name = ArchiveBuilder::current()->ro_strdup(module_name);
575   }
576   ArchivePtrMarker::mark_pointer(&_archived_main_module_name);
577 }
578 
579 void Modules::serialize(SerializeClosure* soc) {
580   soc->do_ptr(&_archived_main_module_name);
581   if (soc->reading()) {
582     const char* runtime_main_module = Arguments::get_property("jdk.module.main");
583     log_info(cds)("_archived_main_module_name %s",
584       _archived_main_module_name != nullptr ? _archived_main_module_name : "(null)");
585     bool disable = false;
586     if (runtime_main_module == nullptr) {
587       if (_archived_main_module_name != nullptr) {
588         log_info(cds)("Module %s specified during dump time but not during runtime", _archived_main_module_name);
589         disable = true;
590       }
591     } else {
592       if (_archived_main_module_name == nullptr) {
593         log_info(cds)("Module %s specified during runtime but not during dump time", runtime_main_module);
594         disable = true;
595       } else if (strcmp(runtime_main_module, _archived_main_module_name) != 0) {
596         log_info(cds)("Mismatched modules: runtime %s dump time %s", runtime_main_module, _archived_main_module_name);
597         disable = true;
598       }
599     }
600 
601     if (disable) {
602       log_info(cds)("Disabling optimized module handling");
603       CDSConfig::stop_using_optimized_module_handling();
604     }
605     log_info(cds)("optimized module handling: %s", CDSConfig::is_using_optimized_module_handling() ? "enabled" : "disabled");
606     log_info(cds)("full module graph: %s", CDSConfig::is_using_full_module_graph() ? "enabled" : "disabled");
607   }
608 }
609 
610 void Modules::define_archived_modules(Handle h_platform_loader, Handle h_system_loader, TRAPS) {
611   assert(CDSConfig::is_using_full_module_graph(), "must be");
612 
613   // We don't want the classes used by the archived full module graph to be redefined by JVMTI.
614   // Luckily, such classes are loaded in the JVMTI "early" phase, and CDS is disabled if a JVMTI
615   // agent wants to redefine classes in this phase.
616   JVMTI_ONLY(assert(JvmtiExport::is_early_phase(), "must be"));
617   assert(!(JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()),
618          "CDS should be disabled if early class hooks are enabled");
619 
620   Handle java_base_module(THREAD, ClassLoaderDataShared::restore_archived_oops_for_null_class_loader_data());
621   // Patch any previously loaded class's module field with java.base's java.lang.Module.
622   ModuleEntryTable::patch_javabase_entries(THREAD, java_base_module);
623 
624   if (h_platform_loader.is_null()) {
625     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null platform loader object");
626   }
627 
628   if (h_system_loader.is_null()) {
629     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null system loader object");
630   }
631 
632   ClassLoaderData* platform_loader_data = SystemDictionary::register_loader(h_platform_loader);
633   SystemDictionary::set_platform_loader(platform_loader_data);
634   ClassLoaderDataShared::restore_java_platform_loader_from_archive(platform_loader_data);
635 
636   ClassLoaderData* system_loader_data = SystemDictionary::register_loader(h_system_loader);
637   SystemDictionary::set_system_loader(system_loader_data);
638   // system_loader_data here is always an instance of jdk.internal.loader.ClassLoader$AppClassLoader.
639   // However, if -Djava.system.class.loader=xxx is specified, java_platform_loader() would
640   // be an instance of a user-defined class, so make sure this never happens.
641   assert(Arguments::get_property("java.system.class.loader") == nullptr,
642            "archived full module should have been disabled if -Djava.system.class.loader is specified");
643   ClassLoaderDataShared::restore_java_system_loader_from_archive(system_loader_data);
644 }
645 
646 void Modules::check_cds_restrictions(Handle module1, Handle module2, TRAPS) {
647   if (CDSConfig::is_dumping_full_module_graph() && Universe::is_module_initialized()) {
648     if (CDSConfig::is_dumping_dynamic_proxies() && (is_dynamic_proxy_module(module1) || is_dynamic_proxy_module(module2))) {
649       // The only the we allow is to add or modify the jdk.proxy?? modules that are used for dynamic proxies.
650     } else {
651       THROW_MSG(vmSymbols::java_lang_UnsupportedOperationException(),
652                 "During -Xshare:dump, module system cannot be modified after it's initialized");
653     }
654   }
655 }
656 
657 #endif // INCLUDE_CDS_JAVA_HEAP
658 
659 bool Modules::is_dynamic_proxy_module(Handle module) {
660   if (!module.is_null()) {
661     ModuleEntry* module_entry = java_lang_Module::module_entry(module());
662     return is_dynamic_proxy_module(module_entry);
663   }
664   return false;
665 }
666 
667 bool Modules::is_dynamic_proxy_module(ModuleEntry* module_entry) {
668   return (module_entry != nullptr && module_entry->is_named() && module_entry->name()->starts_with("jdk.proxy"));
669 }
670 
671 void Modules::set_bootloader_unnamed_module(Handle module, TRAPS) {
672   ResourceMark rm(THREAD);
673 
674   if (module.is_null()) {
675     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
676   }
677   if (!java_lang_Module::is_instance(module())) {
678     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
679               "module is not an instance of type java.lang.Module");
680   }
681 
682   // Ensure that this is an unnamed module
683   oop name = java_lang_Module::name(module());
684   if (name != nullptr) {
685     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
686               "boot loader's unnamed module's java.lang.Module has a name");
687   }
688 
689   // Validate java_base's loader is the boot loader.
690   oop loader = java_lang_Module::loader(module());
691   if (loader != nullptr) {
692     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
693               "Class loader must be the boot class loader");
694   }
695 
696   log_debug(module)("set_bootloader_unnamed_module(): recording unnamed module for boot loader");
697 
698   // Set java.lang.Module for the boot loader's unnamed module
699   ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
700   ModuleEntry* unnamed_module = boot_loader_data->unnamed_module();
701   assert(unnamed_module != nullptr, "boot loader's unnamed ModuleEntry not defined");
702   unnamed_module->set_module(boot_loader_data->add_handle(module));
703   // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
704   java_lang_Module::set_module_entry(module(), unnamed_module);
705 }
706 
707 void Modules::add_module_exports(Handle from_module, jstring package_name, Handle to_module, TRAPS) {
708   check_cds_restrictions(from_module, to_module, CHECK);
709 
710   if (package_name == nullptr) {
711     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
712               "package is null");
713   }
714   if (from_module.is_null()) {
715     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
716               "from_module is null");
717   }
718   ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
719   if (from_module_entry == nullptr) {
720     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
721               "from_module cannot be found");
722   }
723 
724   // All packages in unnamed and open modules are exported by default.
725   if (!from_module_entry->is_named() || from_module_entry->is_open()) return;
726 
727   ModuleEntry* to_module_entry;
728   if (to_module.is_null()) {
729     to_module_entry = nullptr;  // It's an unqualified export.
730   } else {
731     to_module_entry = get_module_entry(to_module, CHECK);
732     if (to_module_entry == nullptr) {
733       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
734                 "to_module is invalid");
735     }
736   }
737 
738   PackageEntry* package_entry = nullptr;
739   char buf[128];
740   int package_len;
741 
742   ResourceMark rm(THREAD);
743   const char* pkg = as_internal_package(JNIHandles::resolve_non_null(package_name), buf, sizeof(buf), package_len);
744   {
745     MutexLocker ml(THREAD, Module_lock);
746     package_entry = get_locked_package_entry(from_module_entry, pkg, package_len);
747     // Do nothing if modules are the same
748     // If the package is not found we'll throw an exception later
749     if (from_module_entry != to_module_entry &&
750         package_entry != nullptr) {
751       package_entry->set_exported(to_module_entry);
752     }
753   }
754 
755   // Handle errors and logging outside locked section
756   if (package_entry == nullptr) {
757     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
758               err_msg("Package %s not found in from_module %s",
759                       pkg != nullptr ? pkg : "",
760                       from_module_entry->name()->as_C_string()));
761   }
762 
763   if (log_is_enabled(Debug, module)) {
764     log_debug(module)("add_module_exports(): package %s in module %s is exported to module %s",
765                       package_entry->name()->as_C_string(),
766                       from_module_entry->name()->as_C_string(),
767                       to_module_entry == nullptr ? "null" :
768                       to_module_entry->is_named() ?
769                       to_module_entry->name()->as_C_string() : UNNAMED_MODULE);
770   }
771 }
772 
773 
774 void Modules::add_module_exports_qualified(Handle from_module, jstring package,
775                                            Handle to_module, TRAPS) {
776   check_cds_restrictions(from_module, to_module, CHECK);
777   if (to_module.is_null()) {
778     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
779               "to_module is null");
780   }
781   add_module_exports(from_module, package, to_module, CHECK);
782 }
783 
784 void Modules::add_reads_module(Handle from_module, Handle to_module, TRAPS) {
785   check_cds_restrictions(from_module, to_module, CHECK);
786   if (from_module.is_null()) {
787     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
788               "from_module is null");
789   }
790 
791   ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
792   if (from_module_entry == nullptr) {
793     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
794               "from_module is not valid");
795   }
796 
797   ModuleEntry* to_module_entry;
798   if (!to_module.is_null()) {
799     to_module_entry = get_module_entry(to_module, CHECK);
800     if (to_module_entry == nullptr) {
801       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
802                 "to_module is invalid");
803     }
804   } else {
805     to_module_entry = nullptr;
806   }
807 
808   ResourceMark rm(THREAD);
809   log_debug(module)("add_reads_module(): Adding read from module %s to module %s",
810                     from_module_entry->is_named() ?
811                     from_module_entry->name()->as_C_string() : UNNAMED_MODULE,
812                     to_module_entry == nullptr ? "all unnamed" :
813                       (to_module_entry->is_named() ?
814                        to_module_entry->name()->as_C_string() : UNNAMED_MODULE));
815 
816   // if modules are the same or if from_module is unnamed then no need to add the read.
817   if (from_module_entry != to_module_entry && from_module_entry->is_named()) {
818     from_module_entry->add_read(to_module_entry);
819   }
820 }
821 
822 // This method is called by JFR and JNI.
823 jobject Modules::get_module(jclass clazz, TRAPS) {
824   assert(ModuleEntryTable::javabase_defined(),
825          "Attempt to call get_module before " JAVA_BASE_NAME " is defined");
826 
827   if (clazz == nullptr) {
828     THROW_MSG_(vmSymbols::java_lang_NullPointerException(),
829                "class is null", nullptr);
830   }
831   oop mirror = JNIHandles::resolve_non_null(clazz);
832   if (mirror == nullptr) {
833     log_debug(module)("get_module(): no mirror, returning nullptr");
834     return nullptr;
835   }
836   if (!java_lang_Class::is_instance(mirror)) {
837     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
838                "Invalid class", nullptr);
839   }
840 
841   oop module = java_lang_Class::module(mirror);
842 
843   assert(module != nullptr, "java.lang.Class module field not set");
844   assert(java_lang_Module::is_instance(module), "module is not an instance of type java.lang.Module");
845 
846   LogTarget(Debug,module) lt;
847   if (lt.is_enabled()) {
848     ResourceMark rm(THREAD);
849     LogStream ls(lt);
850     Klass* klass = java_lang_Class::as_Klass(mirror);
851     oop module_name = java_lang_Module::name(module);
852     if (module_name != nullptr) {
853       ls.print("get_module(): module ");
854       java_lang_String::print(module_name, tty);
855     } else {
856       ls.print("get_module(): Unnamed Module");
857     }
858     if (klass != nullptr) {
859       ls.print_cr(" for class %s", klass->external_name());
860     } else {
861       ls.print_cr(" for primitive class");
862     }
863   }
864 
865   return JNIHandles::make_local(THREAD, module);
866 }
867 
868 oop Modules::get_named_module(Handle h_loader, const char* package_name) {
869   assert(ModuleEntryTable::javabase_defined(),
870          "Attempt to call get_named_module before " JAVA_BASE_NAME " is defined");
871   assert(h_loader.is_null() || java_lang_ClassLoader::is_subclass(h_loader->klass()),
872          "Class loader is not a subclass of java.lang.ClassLoader");
873   assert(package_name != nullptr, "the package_name should not be null");
874 
875   if (strlen(package_name) == 0) {
876     return nullptr;
877   }
878   TempNewSymbol package_sym = SymbolTable::new_symbol(package_name);
879   const PackageEntry* const pkg_entry =
880     get_package_entry_by_name(package_sym, h_loader);
881   const ModuleEntry* const module_entry = (pkg_entry != nullptr ? pkg_entry->module() : nullptr);
882 
883   if (module_entry != nullptr && module_entry->module() != nullptr && module_entry->is_named()) {
884     return module_entry->module();
885   }
886   return nullptr;
887 }
888 
889 // Export package in module to all unnamed modules.
890 void Modules::add_module_exports_to_all_unnamed(Handle module, jstring package_name, TRAPS) {
891   check_cds_restrictions(Handle(), module, CHECK);
892   if (module.is_null()) {
893     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
894               "module is null");
895   }
896   if (package_name == nullptr) {
897     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
898               "package is null");
899   }
900   ModuleEntry* module_entry = get_module_entry(module, CHECK);
901   if (module_entry == nullptr) {
902     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
903               "module is invalid");
904   }
905 
906   // No-op for unnamed module and open modules
907   if (!module_entry->is_named() || module_entry->is_open())
908     return;
909 
910   ResourceMark rm(THREAD);
911   char buf[128];
912   int pkg_len;
913   const char* pkg = as_internal_package(JNIHandles::resolve_non_null(package_name), buf, sizeof(buf), pkg_len);
914   PackageEntry* package_entry = nullptr;
915   {
916     MutexLocker m1(THREAD, Module_lock);
917     package_entry = get_locked_package_entry(module_entry, pkg, pkg_len);
918 
919     // Mark package as exported to all unnamed modules.
920     if (package_entry != nullptr) {
921       package_entry->set_is_exported_allUnnamed();
922     }
923   }
924 
925   // Handle errors and logging outside locked section
926   if (package_entry == nullptr) {
927     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
928               err_msg("Package %s not found in module %s",
929                       pkg != nullptr ? pkg : "",
930                       module_entry->name()->as_C_string()));
931   }
932 
933   if (log_is_enabled(Debug, module)) {
934     log_debug(module)("add_module_exports_to_all_unnamed(): package %s in module"
935                       " %s is exported to all unnamed modules",
936                        package_entry->name()->as_C_string(),
937                        module_entry->name()->as_C_string());
938   }
939 }
--- EOF ---