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/archiveBuilder.hpp"
26 #include "cds/cdsConfig.hpp"
27 #include "cds/metaspaceShared.hpp"
28 #include "classfile/classFileParser.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/classLoaderData.inline.hpp"
31 #include "classfile/classLoaderDataShared.hpp"
32 #include "classfile/classLoaderExt.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 check_cds_restrictions(CHECK);
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
304 // Special handling of java.base definition
305 if (strcmp(module_name, JAVA_BASE_NAME) == 0) {
306 assert(is_open == JNI_FALSE, "java.base module cannot be open");
307 define_javabase_module(module, version, location, packages_h, num_packages, CHECK);
308 return;
309 }
310
311 oop loader = java_lang_Module::loader(module());
312 Handle h_loader = Handle(THREAD, loader);
313 // define_module can be called during start-up, before the class loader's ClassLoaderData
314 // has been created. SystemDictionary::register_loader ensures creation, if needed.
315 ClassLoaderData* loader_data = SystemDictionary::register_loader(h_loader);
316 assert(loader_data != nullptr, "class loader data shouldn't be null");
317
318 // Only modules defined to either the boot or platform class loader, can define a "java/" package.
319 bool java_pkg_disallowed = !h_loader.is_null() &&
320 !SystemDictionary::is_platform_class_loader(h_loader());
321
322 // Check that the list of packages has no duplicates and that the
323 // packages are syntactically ok.
324 char buf[128];
325 GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);
326 for (int x = 0; x < num_packages; x++) {
327 oop pkg_str = packages_h->obj_at(x);
328 if (pkg_str == nullptr || pkg_str->klass() != vmClasses::String_klass()) {
329 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
330 err_msg("Bad package name"));
331 }
332
333 int package_len;
334 const char* package_name = as_internal_package(pkg_str, buf, sizeof(buf), package_len);
335 if (!verify_package_name(package_name, package_len)) {
336 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
337 err_msg("Invalid package name: %s for module: %s",
338 package_name, module_name));
339 }
340
341 // Only modules defined to either the boot or platform class loader, can define a "java/" package.
342 if (java_pkg_disallowed &&
343 (strncmp(package_name, JAVAPKG, JAVAPKG_LEN) == 0 &&
344 (package_name[JAVAPKG_LEN] == JVM_SIGNATURE_SLASH || package_name[JAVAPKG_LEN] == '\0'))) {
345 const char* class_loader_name = loader_data->loader_name_and_id();
346 size_t pkg_len = strlen(package_name);
347 char* pkg_name = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, pkg_len + 1);
348 strncpy(pkg_name, package_name, pkg_len + 1);
349 StringUtils::replace_no_expand(pkg_name, "/", ".");
350 const char* msg_text1 = "Class loader (instance of): ";
351 const char* msg_text2 = " tried to define prohibited package name: ";
352 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + pkg_len + 1;
353 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
354 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, pkg_name);
355 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), message);
356 }
357
358 Symbol* pkg_symbol = SymbolTable::new_symbol(package_name, package_len);
359 pkg_list->append(pkg_symbol);
360 }
361
362 ModuleEntryTable* module_table = get_module_entry_table(h_loader);
363 assert(module_table != nullptr, "module entry table shouldn't be null");
364
365 // Create symbol* entry for module name.
366 TempNewSymbol module_symbol = SymbolTable::new_symbol(module_name, module_name_len);
367
368 bool dupl_modules = false;
369
370 // Create symbol for module version.
371 TempNewSymbol version_symbol = as_symbol(version);
372
373 // Create symbol* entry for module location.
374 TempNewSymbol location_symbol = as_symbol(location);
375
376 PackageEntryTable* package_table = nullptr;
377 PackageEntry* existing_pkg = nullptr;
378 {
379 MutexLocker ml(THREAD, Module_lock);
380
381 if (num_packages > 0) {
382 package_table = get_package_entry_table(h_loader);
383 assert(package_table != nullptr, "Missing package_table");
384
385 // Check that none of the packages exist in the class loader's package table.
386 for (int x = 0; x < pkg_list->length(); x++) {
387 existing_pkg = package_table->locked_lookup_only(pkg_list->at(x));
388 if (existing_pkg != nullptr) {
389 // This could be because the module was already defined. If so,
390 // report that error instead of the package error.
391 if (module_table->lookup_only(module_symbol) != nullptr) {
392 dupl_modules = true;
393 }
394 break;
395 }
396 }
397 } // if (num_packages > 0)...
398
399 // Add the module and its packages.
400 if (!dupl_modules && existing_pkg == nullptr) {
401 if (module_table->lookup_only(module_symbol) == nullptr) {
402 // Create the entry for this module in the class loader's module entry table.
403 ModuleEntry* module_entry = module_table->locked_create_entry(module,
404 (is_open == JNI_TRUE), module_symbol,
405 version_symbol, location_symbol, loader_data);
406 assert(module_entry != nullptr, "module_entry creation failed");
407
408 // Add the packages.
409 assert(pkg_list->length() == 0 || package_table != nullptr, "Bad package table");
410 for (int y = 0; y < pkg_list->length(); y++) {
411 package_table->locked_create_entry(pkg_list->at(y), module_entry);
412
413 // Unable to have a GrowableArray of TempNewSymbol. Must decrement the refcount of
414 // the Symbol* that was created above for each package. The refcount was incremented
415 // by SymbolTable::new_symbol and as well by the PackageEntry creation.
416 pkg_list->at(y)->decrement_refcount();
417 }
418
419 // Store pointer to ModuleEntry record in java.lang.Module object.
420 java_lang_Module::set_module_entry(module(), module_entry);
421 } else {
422 dupl_modules = true;
423 }
424 }
425 } // Release the lock
426
427 // any errors ?
428 if (dupl_modules) {
429 THROW_MSG(vmSymbols::java_lang_IllegalStateException(),
430 err_msg("Module %s is already defined", module_name));
431 } else if (existing_pkg != nullptr) {
432 throw_dup_pkg_exception(module_name, existing_pkg, CHECK);
433 }
434
435 log_info(module, load)("%s location: %s", module_name,
436 location_symbol != nullptr ? location_symbol->as_C_string() : "null");
437 LogTarget(Debug, module) lt;
438 if (lt.is_enabled()) {
439 LogStream ls(lt);
440 ls.print("define_module(): creation of module: %s, version: %s, location: %s, ",
441 module_name, version_symbol != nullptr ? version_symbol->as_C_string() : "null",
442 location_symbol != nullptr ? location_symbol->as_C_string() : "null");
443 loader_data->print_value_on(&ls);
444 ls.print_cr(", package #: %d", pkg_list->length());
445 for (int y = 0; y < pkg_list->length(); y++) {
446 log_trace(module)("define_module(): creation of package %s for module %s",
447 (pkg_list->at(y))->as_C_string(), module_name);
448 }
449 }
450
451 // If the module is defined to the boot loader and an exploded build is being
452 // used, prepend <java.home>/modules/modules_name to the boot class path.
453 if (h_loader.is_null() && !ClassLoader::has_jrt_entry()) {
454 ClassLoader::add_to_exploded_build_list(THREAD, module_symbol);
455 }
456
457 #if COMPILER2_OR_JVMCI
458 // Special handling of jdk.incubator.vector
459 if (strcmp(module_name, "jdk.incubator.vector") == 0) {
460 if (FLAG_IS_DEFAULT(EnableVectorSupport)) {
461 FLAG_SET_DEFAULT(EnableVectorSupport, true);
462 }
463 if (EnableVectorSupport && FLAG_IS_DEFAULT(EnableVectorReboxing)) {
464 FLAG_SET_DEFAULT(EnableVectorReboxing, true);
465 }
466 if (EnableVectorSupport && EnableVectorReboxing && FLAG_IS_DEFAULT(EnableVectorAggressiveReboxing)) {
467 FLAG_SET_DEFAULT(EnableVectorAggressiveReboxing, true);
468 }
469 if (EnableVectorSupport && FLAG_IS_DEFAULT(UseVectorStubs)) {
470 FLAG_SET_DEFAULT(UseVectorStubs, 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 log_info(compilation)("UseVectorStubs=%s", (UseVectorStubs ? "true" : "false"));
476 }
477 #endif // COMPILER2_OR_JVMCI
478 }
479
480 #if INCLUDE_CDS_JAVA_HEAP
481 static bool _seen_platform_unnamed_module = false;
482 static bool _seen_system_unnamed_module = false;
483
484 // Validate the states of an java.lang.Module oop to be archived.
485 void Modules::check_archived_module_oop(oop orig_module_obj) {
486 assert(CDSConfig::is_dumping_full_module_graph(), "must be");
487 assert(java_lang_Module::is_instance(orig_module_obj), "must be");
488
489 ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
490 if (orig_module_ent == nullptr) {
491 // These special java.lang.Module oops are created in Java code. They are not
492 // defined via Modules::define_module(), so they don't have a ModuleEntry:
493 // java.lang.Module::ALL_UNNAMED_MODULE
494 // java.lang.Module::EVERYONE_MODULE
495 // jdk.internal.loader.ClassLoaders$BootClassLoader::unnamedModule
496 log_info(cds, module)("Archived java.lang.Module oop " PTR_FORMAT " with no ModuleEntry*", p2i(orig_module_obj));
497 assert(java_lang_Module::name(orig_module_obj) == nullptr, "must be unnamed");
498 } else {
499 // This java.lang.Module oop has an ModuleEntry*. Check if the latter is archived.
500 if (log_is_enabled(Info, cds, module)) {
501 ResourceMark rm;
502 LogStream ls(Log(cds, module)::info());
503 ls.print("Archived java.lang.Module oop " PTR_FORMAT " for ", p2i(orig_module_obj));
504 orig_module_ent->print(&ls);
505 }
506
507 // We only archive the default module graph, which should contain only java.lang.Module oops
508 // for the 3 built-in loaders (boot/platform/system)
509 ClassLoaderData* loader_data = orig_module_ent->loader_data();
510 assert(loader_data->is_builtin_class_loader_data(), "must be");
511
512 if (orig_module_ent->name() != nullptr) {
513 // For each named module, we archive both the java.lang.Module oop and the ModuleEntry.
514 assert(orig_module_ent->has_been_archived(), "sanity");
515 } else {
516 // We only archive two unnamed module oops (for platform and system loaders). These do NOT have an archived
517 // ModuleEntry.
518 //
519 // At runtime, these oops are fetched from java_lang_ClassLoader::unnamedModule(loader) and
520 // are initialized in ClassLoaderData::ClassLoaderData() => ModuleEntry::create_unnamed_module(), where
521 // a new ModuleEntry is allocated.
522 assert(!loader_data->is_boot_class_loader_data(), "unnamed module for boot loader should be not archived");
523 assert(!orig_module_ent->has_been_archived(), "sanity");
524
525 if (SystemDictionary::is_platform_class_loader(loader_data->class_loader())) {
526 assert(!_seen_platform_unnamed_module, "only once");
527 _seen_platform_unnamed_module = true;
528 } else if (SystemDictionary::is_system_class_loader(loader_data->class_loader())) {
529 assert(!_seen_system_unnamed_module, "only once");
530 _seen_system_unnamed_module = true;
531 } else {
532 // The java.lang.Module oop and ModuleEntry of the unnamed module of the boot loader are
533 // not in the archived module graph. These are always allocated at runtime.
534 ShouldNotReachHere();
535 }
536 }
537 }
538 }
539
540 void Modules::verify_archived_modules() {
541 ModuleEntry::verify_archived_module_entries();
542 }
543
544 class Modules::ArchivedProperty {
545 const char* _prop;
546 const bool _numbered;
547 const char* _archived_value;
548
549 const char* get_flattened_value() const {
550 if (_numbered) {
551 return get_numbered_property_as_sorted_string();
552 } else {
553 return Arguments::get_property(_prop);
554 }
555 }
556
557 void runtime_check() const;
558 const char* get_numbered_property_as_sorted_string() const;
559
560 public:
561 ArchivedProperty(const char* prop, bool numbered)
562 : _prop(prop), _numbered(numbered), _archived_value(nullptr) {}
563
564 void dump() {
565 ResourceMark rm;
566 const char* str = get_flattened_value();
567 if (str != nullptr) {
568 _archived_value = ArchiveBuilder::current()->ro_strdup(str);
569 }
570 }
571
572 void serialize(SerializeClosure* soc) {
573 soc->do_ptr(&_archived_value);
574 if (soc->reading()) {
575 runtime_check();
576 // Don't hold onto the pointer, in case we might decide to unmap the archive.
577 _archived_value = nullptr;
578 }
579 }
580 };
581
582 Modules::ArchivedProperty Modules::_archived_props[] = {
583 // numbered
584 {"jdk.module.main", false},
585
586 // non-numbered
587 {"jdk.module.addexports", true}, // --add-exports
588 {"jdk.module.addmods", true}, // --add-modules
589 {"jdk.module.enable.native.access", true}, // --enable-native-access
590 };
591
592 constexpr size_t Modules::num_archived_props() {
593 return sizeof(_archived_props) / sizeof(_archived_props[0]);
594 }
595
596 Modules::ArchivedProperty& Modules::archived_prop(size_t i) {
597 assert(i < num_archived_props(), "oob");
598 return _archived_props[i];
599 }
600
601 void Modules::ArchivedProperty::runtime_check() const {
602 ResourceMark rm;
603 const char* runtime_value = get_flattened_value();
604 log_info(cds)("archived module property %s: %s", _prop,
605 _archived_value != nullptr ? _archived_value : "(null)");
606
607 bool disable = false;
608 if (runtime_value == nullptr) {
609 if (_archived_value != nullptr) {
610 log_info(cds)("Mismatched values for property %s: %s specified during dump time but not during runtime", _prop, _archived_value);
611 disable = true;
612 }
613 } else {
614 if (_archived_value == nullptr) {
615 log_info(cds)("Mismatched values for property %s: %s specified during runtime but not during dump time", _prop, runtime_value);
616 disable = true;
617 } else if (strcmp(runtime_value, _archived_value) != 0) {
618 log_info(cds)("Mismatched values for property %s: runtime %s dump time %s", _prop, runtime_value, _archived_value);
619 disable = true;
620 }
621 }
622
623 if (disable) {
624 log_info(cds)("Disabling optimized module handling");
625 CDSConfig::stop_using_optimized_module_handling();
626 }
627 }
628
629 // Caller needs ResourceMark
630 const char* Modules::ArchivedProperty::get_numbered_property_as_sorted_string() const {
631 assert(_numbered, "sanity");
632 // theoretical string size limit for decimal int, but the following loop will end much sooner due to
633 // OS command-line size limit.
634 const int max_digits = 10;
635 const int extra_symbols_count = 2; // includes '.', '\0'
636 size_t prop_len = strlen(_prop) + max_digits + extra_symbols_count;
637 char* prop_name = resource_allocate_bytes(prop_len);
638 GrowableArray<const char*> list;
639 for (unsigned int i = 0;; i++) {
640 jio_snprintf(prop_name, prop_len, "%s.%d", _prop, i);
641 const char* prop_value = Arguments::get_property(prop_name);
642 if (prop_value == nullptr) {
643 break;
644 }
645 char* p = resource_allocate_bytes(strlen(prop_value) + 1);
646 strcpy(p, 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 log_info(cds)("optimized module handling: %s", CDSConfig::is_using_optimized_module_handling() ? "enabled" : "disabled");
699 log_info(cds)("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(TRAPS) {
740 if (CDSConfig::is_dumping_full_module_graph() && Universe::is_module_initialized()) {
741 THROW_MSG(vmSymbols::java_lang_UnsupportedOperationException(),
742 "During -Xshare:dump, module system cannot be modified after it's initialized");
743 }
744 }
745 #endif // INCLUDE_CDS_JAVA_HEAP
746
747 void Modules::set_bootloader_unnamed_module(Handle module, TRAPS) {
748 ResourceMark rm(THREAD);
749
750 if (module.is_null()) {
751 THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
752 }
753 if (!java_lang_Module::is_instance(module())) {
754 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
755 "module is not an instance of type java.lang.Module");
756 }
757
758 // Ensure that this is an unnamed module
759 oop name = java_lang_Module::name(module());
760 if (name != nullptr) {
761 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
762 "boot loader's unnamed module's java.lang.Module has a name");
763 }
764
765 // Validate java_base's loader is the boot loader.
766 oop loader = java_lang_Module::loader(module());
767 if (loader != nullptr) {
768 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
769 "Class loader must be the boot class loader");
770 }
771
772 log_debug(module)("set_bootloader_unnamed_module(): recording unnamed module for boot loader");
773
774 // Set java.lang.Module for the boot loader's unnamed module
775 ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
776 ModuleEntry* unnamed_module = boot_loader_data->unnamed_module();
777 assert(unnamed_module != nullptr, "boot loader's unnamed ModuleEntry not defined");
778 unnamed_module->set_module(boot_loader_data->add_handle(module));
779 // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
780 java_lang_Module::set_module_entry(module(), unnamed_module);
781 }
782
783 void Modules::add_module_exports(Handle from_module, jstring package_name, Handle to_module, TRAPS) {
784 check_cds_restrictions(CHECK);
785
786 if (package_name == nullptr) {
787 THROW_MSG(vmSymbols::java_lang_NullPointerException(),
788 "package is null");
789 }
790 if (from_module.is_null()) {
791 THROW_MSG(vmSymbols::java_lang_NullPointerException(),
792 "from_module is null");
793 }
794 ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
795 if (from_module_entry == nullptr) {
796 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
797 "from_module cannot be found");
798 }
799
800 // All packages in unnamed and open modules are exported by default.
801 if (!from_module_entry->is_named() || from_module_entry->is_open()) return;
802
803 ModuleEntry* to_module_entry;
804 if (to_module.is_null()) {
805 to_module_entry = nullptr; // It's an unqualified export.
806 } else {
807 to_module_entry = get_module_entry(to_module, CHECK);
808 if (to_module_entry == nullptr) {
809 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
810 "to_module is invalid");
811 }
812 }
813
814 PackageEntry* package_entry = nullptr;
815 char buf[128];
816 int package_len;
817
818 ResourceMark rm(THREAD);
819 const char* pkg = as_internal_package(JNIHandles::resolve_non_null(package_name), buf, sizeof(buf), package_len);
820 {
821 MutexLocker ml(THREAD, Module_lock);
822 package_entry = get_locked_package_entry(from_module_entry, pkg, package_len);
823 // Do nothing if modules are the same
824 // If the package is not found we'll throw an exception later
825 if (from_module_entry != to_module_entry &&
826 package_entry != nullptr) {
827 package_entry->set_exported(to_module_entry);
828 }
829 }
830
831 // Handle errors and logging outside locked section
832 if (package_entry == nullptr) {
833 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
834 err_msg("Package %s not found in from_module %s",
835 pkg != nullptr ? pkg : "",
836 from_module_entry->name()->as_C_string()));
837 }
838
839 if (log_is_enabled(Debug, module)) {
840 log_debug(module)("add_module_exports(): package %s in module %s is exported to module %s",
841 package_entry->name()->as_C_string(),
842 from_module_entry->name()->as_C_string(),
843 to_module_entry == nullptr ? "null" :
844 to_module_entry->is_named() ?
845 to_module_entry->name()->as_C_string() : UNNAMED_MODULE);
846 }
847 }
848
849
850 void Modules::add_module_exports_qualified(Handle from_module, jstring package,
851 Handle to_module, TRAPS) {
852 check_cds_restrictions(CHECK);
853 if (to_module.is_null()) {
854 THROW_MSG(vmSymbols::java_lang_NullPointerException(),
855 "to_module is null");
856 }
857 add_module_exports(from_module, package, to_module, CHECK);
858 }
859
860 void Modules::add_reads_module(Handle from_module, Handle to_module, TRAPS) {
861 check_cds_restrictions(CHECK);
862 if (from_module.is_null()) {
863 THROW_MSG(vmSymbols::java_lang_NullPointerException(),
864 "from_module is null");
865 }
866
867 ModuleEntry* from_module_entry = get_module_entry(from_module, CHECK);
868 if (from_module_entry == nullptr) {
869 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
870 "from_module is not valid");
871 }
872
873 ModuleEntry* to_module_entry;
874 if (!to_module.is_null()) {
875 to_module_entry = get_module_entry(to_module, CHECK);
876 if (to_module_entry == nullptr) {
877 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
878 "to_module is invalid");
879 }
880 } else {
881 to_module_entry = nullptr;
882 }
883
884 ResourceMark rm(THREAD);
885 log_debug(module)("add_reads_module(): Adding read from module %s to module %s",
886 from_module_entry->is_named() ?
887 from_module_entry->name()->as_C_string() : UNNAMED_MODULE,
888 to_module_entry == nullptr ? "all unnamed" :
889 (to_module_entry->is_named() ?
890 to_module_entry->name()->as_C_string() : UNNAMED_MODULE));
891
892 // if modules are the same or if from_module is unnamed then no need to add the read.
893 if (from_module_entry != to_module_entry && from_module_entry->is_named()) {
894 from_module_entry->add_read(to_module_entry);
895 }
896 }
897
898 // This method is called by JFR and JNI.
899 jobject Modules::get_module(jclass clazz, TRAPS) {
900 assert(ModuleEntryTable::javabase_defined(),
901 "Attempt to call get_module before " JAVA_BASE_NAME " is defined");
902
903 if (clazz == nullptr) {
904 THROW_MSG_(vmSymbols::java_lang_NullPointerException(),
905 "class is null", nullptr);
906 }
907 oop mirror = JNIHandles::resolve_non_null(clazz);
908 if (mirror == nullptr) {
909 log_debug(module)("get_module(): no mirror, returning nullptr");
910 return nullptr;
911 }
912 if (!java_lang_Class::is_instance(mirror)) {
913 THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
914 "Invalid class", nullptr);
915 }
916
917 oop module = java_lang_Class::module(mirror);
918
919 assert(module != nullptr, "java.lang.Class module field not set");
920 assert(java_lang_Module::is_instance(module), "module is not an instance of type java.lang.Module");
921
922 LogTarget(Debug,module) lt;
923 if (lt.is_enabled()) {
924 LogStream ls(lt);
925 Klass* klass = java_lang_Class::as_Klass(mirror);
926 oop module_name = java_lang_Module::name(module);
927 if (module_name != nullptr) {
928 ls.print("get_module(): module ");
929 java_lang_String::print(module_name, tty);
930 } else {
931 ls.print("get_module(): Unnamed Module");
932 }
933 if (klass != nullptr) {
934 ResourceMark rm(THREAD);
935 ls.print_cr(" for class %s", klass->external_name());
936 } else {
937 ls.print_cr(" for primitive class");
938 }
939 }
940
941 return JNIHandles::make_local(THREAD, module);
942 }
943
944 oop Modules::get_named_module(Handle h_loader, const char* package_name) {
945 assert(ModuleEntryTable::javabase_defined(),
946 "Attempt to call get_named_module before " JAVA_BASE_NAME " is defined");
947 assert(h_loader.is_null() || java_lang_ClassLoader::is_subclass(h_loader->klass()),
948 "Class loader is not a subclass of java.lang.ClassLoader");
949 assert(package_name != nullptr, "the package_name should not be null");
950
951 if (strlen(package_name) == 0) {
952 return nullptr;
953 }
954 TempNewSymbol package_sym = SymbolTable::new_symbol(package_name);
955 const PackageEntry* const pkg_entry =
956 get_package_entry_by_name(package_sym, h_loader);
957 const ModuleEntry* const module_entry = (pkg_entry != nullptr ? pkg_entry->module() : nullptr);
958
959 if (module_entry != nullptr && module_entry->module() != nullptr && module_entry->is_named()) {
960 return module_entry->module();
961 }
962 return nullptr;
963 }
964
965 // Export package in module to all unnamed modules.
966 void Modules::add_module_exports_to_all_unnamed(Handle module, jstring package_name, TRAPS) {
967 check_cds_restrictions(CHECK);
968 if (module.is_null()) {
969 THROW_MSG(vmSymbols::java_lang_NullPointerException(),
970 "module is null");
971 }
972 if (package_name == nullptr) {
973 THROW_MSG(vmSymbols::java_lang_NullPointerException(),
974 "package is null");
975 }
976 ModuleEntry* module_entry = get_module_entry(module, CHECK);
977 if (module_entry == nullptr) {
978 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
979 "module is invalid");
980 }
981
982 // No-op for unnamed module and open modules
983 if (!module_entry->is_named() || module_entry->is_open())
984 return;
985
986 ResourceMark rm(THREAD);
987 char buf[128];
988 int pkg_len;
989 const char* pkg = as_internal_package(JNIHandles::resolve_non_null(package_name), buf, sizeof(buf), pkg_len);
990 PackageEntry* package_entry = nullptr;
991 {
992 MutexLocker m1(THREAD, Module_lock);
993 package_entry = get_locked_package_entry(module_entry, pkg, pkg_len);
994
995 // Mark package as exported to all unnamed modules.
996 if (package_entry != nullptr) {
997 package_entry->set_is_exported_allUnnamed();
998 }
999 }
1000
1001 // Handle errors and logging outside locked section
1002 if (package_entry == nullptr) {
1003 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
1004 err_msg("Package %s not found in module %s",
1005 pkg != nullptr ? pkg : "",
1006 module_entry->name()->as_C_string()));
1007 }
1008
1009 if (log_is_enabled(Debug, module)) {
1010 log_debug(module)("add_module_exports_to_all_unnamed(): package %s in module"
1011 " %s is exported to all unnamed modules",
1012 package_entry->name()->as_C_string(),
1013 module_entry->name()->as_C_string());
1014 }
1015 }