1 /*
   2 * Copyright (c) 2016, 2017, 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 "classfile/classFileParser.hpp"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/classLoaderData.inline.hpp"
  29 #include "classfile/javaAssertions.hpp"
  30 #include "classfile/javaClasses.hpp"
  31 #include "classfile/javaClasses.inline.hpp"
  32 #include "classfile/moduleEntry.hpp"
  33 #include "classfile/modules.hpp"
  34 #include "classfile/packageEntry.hpp"
  35 #include "classfile/stringTable.hpp"
  36 #include "classfile/symbolTable.hpp"
  37 #include "classfile/systemDictionary.hpp"
  38 #include "classfile/vmSymbols.hpp"
  39 #include "logging/log.hpp"
  40 #include "logging/logStream.hpp"
  41 #include "memory/resourceArea.hpp"
  42 #include "oops/instanceKlass.hpp"
  43 #include "runtime/arguments.hpp"
  44 #include "runtime/handles.inline.hpp"
  45 #include "runtime/javaCalls.hpp"
  46 #include "runtime/reflection.hpp"
  47 #include "utilities/stringUtils.hpp"
  48 #include "utilities/utf8.hpp"
  49 
  50 static bool verify_module_name(const char *module_name) {
  51   if (module_name == NULL) return false;
  52   int len = (int)strlen(module_name);
  53   return (len > 0 && len <= Symbol::max_length());
  54 }
  55 
  56 bool Modules::verify_package_name(const char* package_name) {
  57   if (package_name == NULL) return false;
  58   int len = (int)strlen(package_name);
  59   return (len > 0 && len <= Symbol::max_length() &&
  60     UTF8::is_legal_utf8((const unsigned char *)package_name, len, false) &&
  61     ClassFileParser::verify_unqualified_name(package_name, len,
  62     ClassFileParser::LegalClass));
  63 }
  64 
  65 static char* get_module_name(oop module, TRAPS) {
  66   oop name_oop = java_lang_Module::name(module);
  67   if (name_oop == NULL) {
  68     THROW_MSG_NULL(vmSymbols::java_lang_NullPointerException(), "Null module name");
  69   }
  70   char* module_name = java_lang_String::as_utf8_string(name_oop);
  71   if (!verify_module_name(module_name)) {
  72     THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),
  73                    err_msg("Invalid module name: %s",
  74                            module_name != NULL ? module_name : "NULL"));
  75   }
  76   return module_name;
  77 }
  78 
  79 static const char* get_module_version(jstring version) {
  80   if (version == NULL) {
  81     return NULL;
  82   }
  83   return java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(version));
  84 }
  85 
  86 static ModuleEntryTable* get_module_entry_table(Handle h_loader, TRAPS) {
  87   // This code can be called during start-up, before the classLoader's classLoader data got
  88   // created.  So, call register_loader() to make sure the classLoader data gets created.
  89   ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader, CHECK_NULL);
  90   return loader_cld->modules();
  91 }
  92 
  93 static PackageEntryTable* get_package_entry_table(Handle h_loader, TRAPS) {
  94   // This code can be called during start-up, before the classLoader's classLoader data got
  95   // created.  So, call register_loader() to make sure the classLoader data gets created.
  96   ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader, CHECK_NULL);
  97   return loader_cld->packages();
  98 }
  99 
 100 static ModuleEntry* get_module_entry(jobject module, TRAPS) {
 101   Handle module_h(THREAD, JNIHandles::resolve(module));
 102   if (!java_lang_Module::is_instance(module_h())) {
 103     THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),
 104                    "module is not an instance of type java.lang.Module");
 105   }
 106   return java_lang_Module::module_entry(module_h(), CHECK_NULL);
 107 }
 108 
 109 static PackageEntry* get_package_entry(ModuleEntry* module_entry, const char* package_name, TRAPS) {
 110   ResourceMark rm(THREAD);
 111   if (package_name == NULL) return NULL;
 112   TempNewSymbol pkg_symbol = SymbolTable::new_symbol(package_name, CHECK_NULL);
 113   PackageEntryTable* package_entry_table = module_entry->loader_data()->packages();
 114   assert(package_entry_table != NULL, "Unexpected null package entry table");
 115   return package_entry_table->lookup_only(pkg_symbol);
 116 }
 117 
 118 static PackageEntry* get_package_entry_by_name(Symbol* package,
 119                                                Handle h_loader,
 120                                                TRAPS) {
 121   if (package != NULL) {
 122     ResourceMark rm(THREAD);
 123     if (Modules::verify_package_name(package->as_C_string())) {
 124       PackageEntryTable* const package_entry_table =
 125         get_package_entry_table(h_loader, CHECK_NULL);
 126       assert(package_entry_table != NULL, "Unexpected null package entry table");
 127       return package_entry_table->lookup_only(package);
 128     }
 129   }
 130   return NULL;
 131 }
 132 
 133 bool Modules::is_package_defined(Symbol* package, Handle h_loader, TRAPS) {
 134   PackageEntry* res = get_package_entry_by_name(package, h_loader, CHECK_false);
 135   return res != NULL;
 136 }
 137 
 138 static void define_javabase_module(jobject module, jstring version,
 139                                    jstring location, const char* const* packages,
 140                                    jsize num_packages, TRAPS) {
 141   ResourceMark rm(THREAD);
 142 
 143   Handle module_handle(THREAD, JNIHandles::resolve(module));
 144 
 145   // Obtain java.base's module version
 146   const char* module_version = get_module_version(version);
 147   TempNewSymbol version_symbol;
 148   if (module_version != NULL) {
 149     version_symbol = SymbolTable::new_symbol(module_version, CHECK);
 150   } else {
 151     version_symbol = NULL;
 152   }
 153 
 154   // Obtain java.base's location
 155   const char* module_location = NULL;
 156   TempNewSymbol location_symbol = NULL;
 157   if (location != NULL) {
 158     module_location =
 159       java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(location));
 160     if (module_location != NULL) {
 161       location_symbol = SymbolTable::new_symbol(module_location, CHECK);
 162     }
 163   }
 164 
 165 
 166   // Check that the packages are syntactically ok.
 167   GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);
 168   for (int x = 0; x < num_packages; x++) {
 169     const char *package_name = packages[x];
 170     if (!Modules::verify_package_name(package_name)) {
 171       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 172                 err_msg("Invalid package name: %s for module: " JAVA_BASE_NAME, package_name));
 173     }
 174     Symbol* pkg_symbol = SymbolTable::new_symbol(package_name, CHECK);
 175     pkg_list->append(pkg_symbol);
 176   }
 177 
 178   // Validate java_base's loader is the boot loader.
 179   oop loader = java_lang_Module::loader(module_handle());
 180   if (loader != NULL) {
 181     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 182               "Class loader must be the boot class loader");
 183   }
 184   Handle h_loader(THREAD, loader);
 185 
 186   // Ensure the boot loader's PackageEntryTable has been created
 187   PackageEntryTable* package_table = get_package_entry_table(h_loader, CHECK);
 188   assert(pkg_list->length() == 0 || package_table != NULL, "Bad package_table");
 189 
 190   // Ensure java.base's ModuleEntry has been created
 191   assert(ModuleEntryTable::javabase_moduleEntry() != NULL, "No ModuleEntry for " JAVA_BASE_NAME);
 192 
 193   bool duplicate_javabase = false;
 194   {
 195     MutexLocker m1(Module_lock, THREAD);
 196 
 197     if (ModuleEntryTable::javabase_defined()) {
 198       duplicate_javabase = true;
 199     } else {
 200 
 201       // Verify that all java.base packages created during bootstrapping are in
 202       // pkg_list.  If any are not in pkg_list, than a non-java.base class was
 203       // loaded erroneously pre java.base module definition.
 204       package_table->verify_javabase_packages(pkg_list);
 205 
 206       // loop through and add any new packages for java.base
 207       PackageEntry* pkg;
 208       for (int x = 0; x < pkg_list->length(); x++) {
 209         // Some of java.base's packages were added early in bootstrapping, ignore duplicates.
 210         if (package_table->lookup_only(pkg_list->at(x)) == NULL) {
 211           pkg = package_table->locked_create_entry_or_null(pkg_list->at(x), ModuleEntryTable::javabase_moduleEntry());
 212           assert(pkg != NULL, "Unable to create a " JAVA_BASE_NAME " package entry");
 213         }
 214         // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of
 215         // the Symbol* that was created above for each package. The refcount was incremented
 216         // by SymbolTable::new_symbol and as well by the PackageEntry creation.
 217         pkg_list->at(x)->decrement_refcount();
 218       }
 219 
 220       // Finish defining java.base's ModuleEntry
 221       ModuleEntryTable::finalize_javabase(module_handle, version_symbol, location_symbol);
 222     }
 223   }
 224   if (duplicate_javabase) {
 225     THROW_MSG(vmSymbols::java_lang_InternalError(),
 226               "Module " JAVA_BASE_NAME " is already defined");
 227   }
 228 
 229   // Only the thread that actually defined the base module will get here,
 230   // so no locking is needed.
 231 
 232   // Patch any previously loaded class's module field with java.base's java.lang.Module.
 233   ModuleEntryTable::patch_javabase_entries(module_handle);
 234 
 235   log_info(module, load)(JAVA_BASE_NAME " location: %s",
 236                          module_location != NULL ? module_location : "NULL");
 237   log_debug(module)("define_javabase_module(): Definition of module: "
 238                     JAVA_BASE_NAME ", version: %s, location: %s, package #: %d",
 239                     module_version != NULL ? module_version : "NULL",
 240                     module_location != NULL ? module_location : "NULL",
 241                     pkg_list->length());
 242 
 243   // packages defined to java.base
 244   if (log_is_enabled(Trace, module)) {
 245     for (int x = 0; x < pkg_list->length(); x++) {
 246       log_trace(module)("define_javabase_module(): creation of package %s for module " JAVA_BASE_NAME,
 247                         (pkg_list->at(x))->as_C_string());
 248     }
 249   }
 250 }
 251 
 252 // Caller needs ResourceMark.
 253 void throw_dup_pkg_exception(const char* module_name, PackageEntry* package, TRAPS) {
 254   const char* package_name = package->name()->as_C_string();
 255   if (package->module()->is_named()) {
 256     THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
 257       err_msg("Package %s for module %s is already in another module, %s, defined to the class loader",
 258               package_name, module_name, package->module()->name()->as_C_string()));
 259   } else {
 260     THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
 261       err_msg("Package %s for module %s is already in the unnamed module defined to the class loader",
 262               package_name, module_name));
 263   }
 264 }
 265 
 266 void Modules::define_module(jobject module, jboolean is_open, jstring version,
 267                             jstring location, const char* const* packages,
 268                             jsize num_packages, TRAPS) {
 269   ResourceMark rm(THREAD);
 270 
 271   if (module == NULL) {
 272     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
 273   }
 274 
 275   if (num_packages < 0) {
 276     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 277               "num_packages must be >= 0");
 278   }
 279 
 280   if (packages == NULL && num_packages > 0) {
 281     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 282               "num_packages should be zero if packages is null");
 283   }
 284 
 285   Handle module_handle(THREAD, JNIHandles::resolve(module));
 286   if (!java_lang_Module::is_instance(module_handle())) {
 287     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 288               "module is not an instance of type java.lang.Module");
 289   }
 290 
 291   char* module_name = get_module_name(module_handle(), CHECK);
 292   if (module_name == NULL) {
 293     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 294               "Module name cannot be null");
 295   }
 296 
 297   // Special handling of java.base definition
 298   if (strcmp(module_name, JAVA_BASE_NAME) == 0) {
 299     assert(is_open == JNI_FALSE, "java.base module cannot be open");
 300     define_javabase_module(module, version, location, packages, num_packages, CHECK);
 301     return;
 302   }
 303 
 304   const char* module_version = get_module_version(version);
 305 
 306   oop loader = java_lang_Module::loader(module_handle());
 307   // Make sure loader is not the jdk.internal.reflect.DelegatingClassLoader.
 308   if (loader != java_lang_ClassLoader::non_reflection_class_loader(loader)) {
 309     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 310               "Class loader is an invalid delegating class loader");
 311   }
 312   Handle h_loader = Handle(THREAD, loader);
 313 
 314   // Check that the list of packages has no duplicates and that the
 315   // packages are syntactically ok.
 316   GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);
 317   for (int x = 0; x < num_packages; x++) {
 318     const char* package_name = packages[x];
 319     if (!verify_package_name(package_name)) {
 320       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 321                 err_msg("Invalid package name: %s for module: %s",
 322                         package_name, module_name));
 323     }
 324 
 325     // Only modules defined to either the boot or platform class loader, can define a "java/" package.
 326     if (!h_loader.is_null() &&
 327         !SystemDictionary::is_platform_class_loader(h_loader()) &&
 328         (strncmp(package_name, JAVAPKG, JAVAPKG_LEN) == 0 &&
 329           (package_name[JAVAPKG_LEN] == '/' || package_name[JAVAPKG_LEN] == '\0'))) {
 330       const char* class_loader_name = SystemDictionary::loader_name(h_loader());
 331       size_t pkg_len = strlen(package_name);
 332       char* pkg_name = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, pkg_len);
 333       strncpy(pkg_name, package_name, pkg_len);
 334       StringUtils::replace_no_expand(pkg_name, "/", ".");
 335       const char* msg_text1 = "Class loader (instance of): ";
 336       const char* msg_text2 = " tried to define prohibited package name: ";
 337       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + pkg_len + 1;
 338       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
 339       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, pkg_name);
 340       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), message);
 341     }
 342 
 343     Symbol* pkg_symbol = SymbolTable::new_symbol(package_name, CHECK);
 344     pkg_list->append(pkg_symbol);
 345   }
 346 
 347   ModuleEntryTable* module_table = get_module_entry_table(h_loader, CHECK);
 348   assert(module_table != NULL, "module entry table shouldn't be null");
 349 
 350   // Create symbol* entry for module name.
 351   TempNewSymbol module_symbol = SymbolTable::new_symbol(module_name, CHECK);
 352 
 353   bool dupl_modules = false;
 354 
 355   // Create symbol* entry for module version.
 356   TempNewSymbol version_symbol;
 357   if (module_version != NULL) {
 358     version_symbol = SymbolTable::new_symbol(module_version, CHECK);
 359   } else {
 360     version_symbol = NULL;
 361   }
 362 
 363   // Create symbol* entry for module location.
 364   const char* module_location = NULL;
 365   TempNewSymbol location_symbol = NULL;
 366   if (location != NULL) {
 367     module_location =
 368       java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(location));
 369     if (module_location != NULL) {
 370       location_symbol = SymbolTable::new_symbol(module_location, CHECK);
 371     }
 372   }
 373 
 374   ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(h_loader());
 375   assert(loader_data != NULL, "class loader data shouldn't be null");
 376 
 377   PackageEntryTable* package_table = NULL;
 378   PackageEntry* existing_pkg = NULL;
 379   {
 380     MutexLocker ml(Module_lock, THREAD);
 381 
 382     if (num_packages > 0) {
 383       package_table = get_package_entry_table(h_loader, CHECK);
 384       assert(package_table != NULL, "Missing package_table");
 385 
 386       // Check that none of the packages exist in the class loader's package table.
 387       for (int x = 0; x < pkg_list->length(); x++) {
 388         existing_pkg = package_table->lookup_only(pkg_list->at(x));
 389         if (existing_pkg != NULL) {
 390           // This could be because the module was already defined.  If so,
 391           // report that error instead of the package error.
 392           if (module_table->lookup_only(module_symbol) != NULL) {
 393             dupl_modules = true;
 394           }
 395           break;
 396         }
 397       }
 398     }  // if (num_packages > 0)...
 399 
 400     // Add the module and its packages.
 401     if (!dupl_modules && existing_pkg == NULL) {
 402       // Create the entry for this module in the class loader's module entry table.
 403       ModuleEntry* module_entry = module_table->locked_create_entry_or_null(module_handle,
 404                                     (is_open == JNI_TRUE), module_symbol,
 405                                     version_symbol, location_symbol, loader_data);
 406 
 407       if (module_entry == NULL) {
 408         dupl_modules = true;
 409       } else {
 410         // Add the packages.
 411         assert(pkg_list->length() == 0 || package_table != NULL, "Bad package table");
 412         PackageEntry* pkg;
 413         for (int y = 0; y < pkg_list->length(); y++) {
 414           pkg = package_table->locked_create_entry_or_null(pkg_list->at(y), module_entry);
 415           assert(pkg != NULL, "Unable to create a module's package entry");
 416 
 417           // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of
 418           // the Symbol* that was created above for each package. The refcount was incremented
 419           // by SymbolTable::new_symbol and as well by the PackageEntry creation.
 420           pkg_list->at(y)->decrement_refcount();
 421         }
 422 
 423         // Store pointer to ModuleEntry record in java.lang.Module object.
 424         java_lang_Module::set_module_entry(module_handle(), module_entry);
 425       }
 426     }
 427   }  // Release the lock
 428 
 429   // any errors ?
 430   if (dupl_modules) {
 431      THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
 432                err_msg("Module %s is already defined", module_name));
 433   } else if (existing_pkg != NULL) {
 434       throw_dup_pkg_exception(module_name, existing_pkg, CHECK);
 435   }
 436 
 437   log_info(module, load)("%s location: %s", module_name,
 438                          module_location != NULL ? module_location : "NULL");
 439   LogTarget(Debug, module) lt;
 440   if (lt.is_enabled()) {
 441     LogStream ls(lt);
 442     ls.print("define_module(): creation of module: %s, version: %s, location: %s, ",
 443                  module_name, module_version != NULL ? module_version : "NULL",
 444                  module_location != NULL ? module_location : "NULL");
 445     loader_data->print_value_on(&ls);
 446     ls.print_cr(", package #: %d", pkg_list->length());
 447     for (int y = 0; y < pkg_list->length(); y++) {
 448       log_trace(module)("define_module(): creation of package %s for module %s",
 449                         (pkg_list->at(y))->as_C_string(), module_name);
 450     }
 451   }
 452 
 453   // If the module is defined to the boot loader and an exploded build is being
 454   // used, prepend <java.home>/modules/modules_name to the system boot class path.
 455   if (loader == NULL && !ClassLoader::has_jrt_entry()) {
 456     ClassLoader::add_to_exploded_build_list(module_symbol, CHECK);
 457   }
 458 }
 459 
 460 void Modules::set_bootloader_unnamed_module(jobject module, TRAPS) {
 461   ResourceMark rm(THREAD);
 462 
 463   if (module == NULL) {
 464     THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
 465   }
 466   Handle module_handle(THREAD, JNIHandles::resolve(module));
 467   if (!java_lang_Module::is_instance(module_handle())) {
 468     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 469               "module is not an instance of type java.lang.Module");
 470   }
 471 
 472   // Ensure that this is an unnamed module
 473   oop name = java_lang_Module::name(module_handle());
 474   if (name != NULL) {
 475     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 476               "boot loader's unnamed module's java.lang.Module has a name");
 477   }
 478 
 479   // Validate java_base's loader is the boot loader.
 480   oop loader = java_lang_Module::loader(module_handle());
 481   if (loader != NULL) {
 482     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 483               "Class loader must be the boot class loader");
 484   }
 485   Handle h_loader(THREAD, loader);
 486 
 487   log_debug(module)("set_bootloader_unnamed_module(): recording unnamed module for boot loader");
 488 
 489   // Set java.lang.Module for the boot loader's unnamed module
 490   ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
 491   ModuleEntry* unnamed_module = boot_loader_data->unnamed_module();
 492   assert(unnamed_module != NULL, "boot loader's unnamed ModuleEntry not defined");
 493   unnamed_module->set_module(boot_loader_data->add_handle(module_handle));
 494   // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
 495   java_lang_Module::set_module_entry(module_handle(), unnamed_module);
 496 }
 497 
 498 void Modules::add_module_exports(jobject from_module, const char* package_name, jobject to_module, TRAPS) {
 499   if (package_name == NULL) {
 500     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 501               "package is null");
 502   }
 503   if (from_module == NULL) {
 504     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 505               "from_module is null");
 506   }
 507   ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
 508   if (from_module_entry == NULL) {
 509     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 510               "from_module cannot be found");
 511   }
 512 
 513   // All packages in unnamed and open modules are exported by default.
 514   if (!from_module_entry->is_named() || from_module_entry->is_open()) return;
 515 
 516   ModuleEntry* to_module_entry;
 517   if (to_module == NULL) {
 518     to_module_entry = NULL;  // It's an unqualified export.
 519   } else {
 520     to_module_entry = get_module_entry(to_module, CHECK);
 521     if (to_module_entry == NULL) {
 522       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 523                 "to_module is invalid");
 524     }
 525   }
 526 
 527   PackageEntry *package_entry = get_package_entry(from_module_entry, package_name, CHECK);
 528   ResourceMark rm(THREAD);
 529   if (package_entry == NULL) {
 530     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 531               err_msg("Package %s not found in from_module %s",
 532                       package_name != NULL ? package_name : "",
 533                       from_module_entry->name()->as_C_string()));
 534   }
 535   if (package_entry->module() != from_module_entry) {
 536     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 537               err_msg("Package: %s found in module %s, not in from_module: %s",
 538                       package_entry->name()->as_C_string(),
 539                       package_entry->module()->name()->as_C_string(),
 540                       from_module_entry->name()->as_C_string()));
 541   }
 542 
 543   log_debug(module)("add_module_exports(): package %s in module %s is exported to module %s",
 544                     package_entry->name()->as_C_string(),
 545                     from_module_entry->name()->as_C_string(),
 546                     to_module_entry == NULL ? "NULL" :
 547                       to_module_entry->is_named() ?
 548                         to_module_entry->name()->as_C_string() : UNNAMED_MODULE);
 549 
 550   // Do nothing if modules are the same.
 551   if (from_module_entry != to_module_entry) {
 552     package_entry->set_exported(to_module_entry);
 553   }
 554 }
 555 
 556 
 557 void Modules::add_module_exports_qualified(jobject from_module, const char* package,
 558                                            jobject to_module, TRAPS) {
 559   if (to_module == NULL) {
 560     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 561               "to_module is null");
 562   }
 563   add_module_exports(from_module, package, to_module, CHECK);
 564 }
 565 
 566 void Modules::add_reads_module(jobject from_module, jobject to_module, TRAPS) {
 567   if (from_module == NULL) {
 568     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 569               "from_module is null");
 570   }
 571 
 572   ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
 573   if (from_module_entry == NULL) {
 574     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 575               "from_module is not valid");
 576   }
 577 
 578   ModuleEntry* to_module_entry;
 579   if (to_module != NULL) {
 580     to_module_entry = get_module_entry(to_module, CHECK);
 581     if (to_module_entry == NULL) {
 582       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 583                 "to_module is invalid");
 584     }
 585   } else {
 586     to_module_entry = NULL;
 587   }
 588 
 589   ResourceMark rm(THREAD);
 590   log_debug(module)("add_reads_module(): Adding read from module %s to module %s",
 591                     from_module_entry->is_named() ?
 592                     from_module_entry->name()->as_C_string() : UNNAMED_MODULE,
 593                     to_module_entry == NULL ? "all unnamed" :
 594                       (to_module_entry->is_named() ?
 595                        to_module_entry->name()->as_C_string() : UNNAMED_MODULE));
 596 
 597   // if modules are the same or if from_module is unnamed then no need to add the read.
 598   if (from_module_entry != to_module_entry && from_module_entry->is_named()) {
 599     from_module_entry->add_read(to_module_entry);
 600   }
 601 }
 602 
 603 // This method is called by JFR and JNI.
 604 jobject Modules::get_module(jclass clazz, TRAPS) {
 605   assert(ModuleEntryTable::javabase_defined(),
 606          "Attempt to call get_module before " JAVA_BASE_NAME " is defined");
 607 
 608   if (clazz == NULL) {
 609     THROW_MSG_(vmSymbols::java_lang_NullPointerException(),
 610                "class is null", JNI_FALSE);
 611   }
 612   oop mirror = JNIHandles::resolve_non_null(clazz);
 613   if (mirror == NULL) {
 614     log_debug(module)("get_module(): no mirror, returning NULL");
 615     return NULL;
 616   }
 617   if (!java_lang_Class::is_instance(mirror)) {
 618     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
 619                "Invalid class", JNI_FALSE);
 620   }
 621 
 622   oop module = java_lang_Class::module(mirror);
 623 
 624   assert(module != NULL, "java.lang.Class module field not set");
 625   assert(java_lang_Module::is_instance(module), "module is not an instance of type java.lang.Module");
 626 
 627   LogTarget(Debug,module) lt;
 628   if (lt.is_enabled()) {
 629     ResourceMark rm(THREAD);
 630     LogStream ls(lt);
 631     Klass* klass = java_lang_Class::as_Klass(mirror);
 632     oop module_name = java_lang_Module::name(module);
 633     if (module_name != NULL) {
 634       ls.print("get_module(): module ");
 635       java_lang_String::print(module_name, tty);
 636     } else {
 637       ls.print("get_module(): Unamed Module");
 638     }
 639     if (klass != NULL) {
 640       ls.print_cr(" for class %s", klass->external_name());
 641     } else {
 642       ls.print_cr(" for primitive class");
 643     }
 644   }
 645 
 646   return JNIHandles::make_local(THREAD, module);
 647 }
 648 
 649 jobject Modules::get_named_module(Handle h_loader, const char* package_name, TRAPS) {
 650   assert(ModuleEntryTable::javabase_defined(),
 651          "Attempt to call get_named_module before " JAVA_BASE_NAME " is defined");
 652   assert(h_loader.is_null() || java_lang_ClassLoader::is_subclass(h_loader->klass()),
 653          "Class loader is not a subclass of java.lang.ClassLoader");
 654   assert(package_name != NULL, "the package_name should not be NULL");
 655 
 656   if (strlen(package_name) == 0) {
 657     return NULL;
 658   }
 659   TempNewSymbol package_sym = SymbolTable::new_symbol(package_name, CHECK_NULL);
 660   const PackageEntry* const pkg_entry =
 661     get_package_entry_by_name(package_sym, h_loader, THREAD);
 662   const ModuleEntry* const module_entry = (pkg_entry != NULL ? pkg_entry->module() : NULL);
 663 
 664   if (module_entry != NULL && module_entry->module() != NULL && module_entry->is_named()) {
 665     return JNIHandles::make_local(THREAD, JNIHandles::resolve(module_entry->module()));
 666   }
 667   return NULL;
 668 }
 669 
 670 
 671 // This method is called by JFR and by the above method.
 672 jobject Modules::get_module(Symbol* package_name, Handle h_loader, TRAPS) {
 673   const PackageEntry* const pkg_entry =
 674     get_package_entry_by_name(package_name, h_loader, THREAD);
 675   const ModuleEntry* const module_entry = (pkg_entry != NULL ? pkg_entry->module() : NULL);
 676 
 677   if (module_entry != NULL &&
 678       module_entry->module() != NULL) {
 679     return JNIHandles::make_local(THREAD, JNIHandles::resolve(module_entry->module()));
 680   }
 681 
 682   return NULL;
 683 }
 684 
 685 void Modules::add_module_package(jobject module, const char* package_name, TRAPS) {
 686   ResourceMark rm(THREAD);
 687 
 688   if (module == NULL) {
 689     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 690               "module is null");
 691   }
 692   if (package_name == NULL) {
 693     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 694               "package is null");
 695   }
 696   ModuleEntry* module_entry = get_module_entry(module, CHECK);
 697   if (module_entry == NULL) {
 698     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 699               "module is invalid");
 700   }
 701   if (!module_entry->is_named()) {
 702     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 703               "module cannot be an unnamed module");
 704   }
 705   if (!verify_package_name(package_name)) {
 706     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 707               err_msg("Invalid package name: %s", package_name));
 708   }
 709 
 710   ClassLoaderData *loader_data = module_entry->loader_data();
 711 
 712   // Only modules defined to either the boot or platform class loader, can define a "java/" package.
 713   if (!loader_data->is_the_null_class_loader_data() &&
 714       !loader_data->is_platform_class_loader_data() &&
 715       (strncmp(package_name, JAVAPKG, JAVAPKG_LEN) == 0 &&
 716         (package_name[JAVAPKG_LEN] == '/' || package_name[JAVAPKG_LEN] == '\0'))) {
 717     const char* class_loader_name = SystemDictionary::loader_name(loader_data);
 718     size_t pkg_len = strlen(package_name);
 719     char* pkg_name = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, pkg_len);
 720     strncpy(pkg_name, package_name, pkg_len);
 721     StringUtils::replace_no_expand(pkg_name, "/", ".");
 722     const char* msg_text1 = "Class loader (instance of): ";
 723     const char* msg_text2 = " tried to define prohibited package name: ";
 724     size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + pkg_len + 1;
 725     char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
 726     jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, pkg_name);
 727     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), message);
 728   }
 729 
 730   log_debug(module)("add_module_package(): Adding package %s to module %s",
 731                     package_name, module_entry->name()->as_C_string());
 732 
 733   TempNewSymbol pkg_symbol = SymbolTable::new_symbol(package_name, CHECK);
 734   PackageEntryTable* package_table = loader_data->packages();
 735   assert(package_table != NULL, "Missing package_table");
 736 
 737   PackageEntry* existing_pkg = NULL;
 738   {
 739     MutexLocker ml(Module_lock, THREAD);
 740 
 741     // Check that the package does not exist in the class loader's package table.
 742     existing_pkg = package_table->lookup_only(pkg_symbol);
 743     if (existing_pkg == NULL) {
 744       PackageEntry* pkg = package_table->locked_create_entry_or_null(pkg_symbol, module_entry);
 745       assert(pkg != NULL, "Unable to create a module's package entry");
 746     }
 747   }
 748   if (existing_pkg != NULL) {
 749     throw_dup_pkg_exception(module_entry->name()->as_C_string(), existing_pkg, CHECK);
 750   }
 751 }
 752 
 753 // Export package in module to all unnamed modules.
 754 void Modules::add_module_exports_to_all_unnamed(jobject module, const char* package_name, TRAPS) {
 755   if (module == NULL) {
 756     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 757               "module is null");
 758   }
 759   if (package_name == NULL) {
 760     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
 761               "package is null");
 762   }
 763   ModuleEntry* module_entry = get_module_entry(module, CHECK);
 764   if (module_entry == NULL) {
 765     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 766               "module is invalid");
 767   }
 768 
 769   if (module_entry->is_named()) { // No-op for unnamed module.
 770     PackageEntry *package_entry = get_package_entry(module_entry, package_name, CHECK);
 771     ResourceMark rm(THREAD);
 772     if (package_entry == NULL) {
 773       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 774                 err_msg("Package %s not found in module %s",
 775                         package_name != NULL ? package_name : "",
 776                         module_entry->name()->as_C_string()));
 777     }
 778     if (package_entry->module() != module_entry) {
 779       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 780                 err_msg("Package: %s found in module %s, not in module: %s",
 781                         package_entry->name()->as_C_string(),
 782                         package_entry->module()->name()->as_C_string(),
 783                         module_entry->name()->as_C_string()));
 784     }
 785 
 786     log_debug(module)("add_module_exports_to_all_unnamed(): package %s in module"
 787                       " %s is exported to all unnamed modules",
 788                        package_entry->name()->as_C_string(),
 789                        module_entry->name()->as_C_string());
 790 
 791     // Mark package as exported to all unnamed modules.
 792     package_entry->set_is_exported_allUnnamed();
 793   }
 794 }