/*

* Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.

* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

*

* This code is free software; you can redistribute it and/or modify it

* under the terms of the GNU General Public License version 2 only, as

* published by the Free Software Foundation.

*

* This code is distributed in the hope that it will be useful, but WITHOUT

* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

* version 2 for more details (a copy is included in the LICENSE file that

* accompanied this code).

*

* You should have received a copy of the GNU General Public License version

* 2 along with this work; if not, write to the Free Software Foundation,

* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

*

* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

* or visit www.oracle.com if you need additional information or have any

* questions.

*

*/

#include "precompiled.hpp"

#include "jvm.h"

#include "classfile/classFileParser.hpp"

#include "classfile/classLoader.hpp"

#include "classfile/classLoaderData.inline.hpp"

#include "classfile/javaAssertions.hpp"

#include "classfile/javaClasses.hpp"

#include "classfile/javaClasses.inline.hpp"

#include "classfile/moduleEntry.hpp"

#include "classfile/modules.hpp"

#include "classfile/packageEntry.hpp"

#include "classfile/stringTable.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/vmSymbols.hpp"

#include "logging/log.hpp"

#include "logging/logStream.hpp"

#include "memory/resourceArea.hpp"

#include "oops/instanceKlass.hpp"

#include "runtime/arguments.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/jniHandles.inline.hpp"

#include "runtime/reflection.hpp"

#include "utilities/stringUtils.hpp"

#include "utilities/utf8.hpp"

static bool verify_module_name(const char *module_name) {

  if (module_name == NULL) return false;

  int len = (int)strlen(module_name);

  return (len > 0 && len <= Symbol::max_length());

}

bool Modules::verify_package_name(const char* package_name) {

  if (package_name == NULL) return false;

  int len = (int)strlen(package_name);

  return (len > 0 && len <= Symbol::max_length() &&

    UTF8::is_legal_utf8((const unsigned char *)package_name, len, false) &&

    ClassFileParser::verify_unqualified_name(package_name, len,

    ClassFileParser::LegalClass));

}

static char* get_module_name(oop module, TRAPS) {

  oop name_oop = java_lang_Module::name(module);

  if (name_oop == NULL) {

    THROW_MSG_NULL(vmSymbols::java_lang_NullPointerException(), "Null module name");

  }

  char* module_name = java_lang_String::as_utf8_string(name_oop);

  if (!verify_module_name(module_name)) {

    THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),

                   err_msg("Invalid module name: %s",

                           module_name != NULL ? module_name : "NULL"));

  }

  return module_name;

}

static const char* get_module_version(jstring version) {

  if (version == NULL) {

    return NULL;

  }

  return java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(version));

}

ModuleEntryTable* Modules::get_module_entry_table(Handle h_loader) {

  // This code can be called during start-up, before the classLoader's classLoader data got

  // created.  So, call register_loader() to make sure the classLoader data gets created.

  ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader);

  return loader_cld->modules();

}

static PackageEntryTable* get_package_entry_table(Handle h_loader) {

  // This code can be called during start-up, before the classLoader's classLoader data got

  // created.  So, call register_loader() to make sure the classLoader data gets created.

  ClassLoaderData *loader_cld = SystemDictionary::register_loader(h_loader);

  return loader_cld->packages();

}

static ModuleEntry* get_module_entry(jobject module, TRAPS) {

  oop m = JNIHandles::resolve(module);

  if (!java_lang_Module::is_instance(m)) {

    THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(),

                   "module is not an instance of type java.lang.Module");

  }

  return java_lang_Module::module_entry(m);

}

static PackageEntry* get_package_entry(ModuleEntry* module_entry, const char* package_name, TRAPS) {

  ResourceMark rm(THREAD);

  if (package_name == NULL) return NULL;

  TempNewSymbol pkg_symbol = SymbolTable::new_symbol(package_name);

  PackageEntryTable* package_entry_table = module_entry->loader_data()->packages();

  assert(package_entry_table != NULL, "Unexpected null package entry table");

  return package_entry_table->lookup_only(pkg_symbol);

}

static PackageEntry* get_package_entry_by_name(Symbol* package,

                                               Handle h_loader,

                                               TRAPS) {

  if (package != NULL) {

    ResourceMark rm(THREAD);

    if (Modules::verify_package_name(package->as_C_string())) {

      PackageEntryTable* const package_entry_table =

        get_package_entry_table(h_loader);

      assert(package_entry_table != NULL, "Unexpected null package entry table");

      return package_entry_table->lookup_only(package);

    }

  }

  return NULL;

}

bool Modules::is_package_defined(Symbol* package, Handle h_loader, TRAPS) {

  PackageEntry* res = get_package_entry_by_name(package, h_loader, CHECK_false);

  return res != NULL;

}

static void define_javabase_module(jobject module, jstring version,

                                   jstring location, const char* const* packages,

                                   jsize num_packages, TRAPS) {

  ResourceMark rm(THREAD);

  Handle module_handle(THREAD, JNIHandles::resolve(module));

  // Obtain java.base's module version

  const char* module_version = get_module_version(version);

  TempNewSymbol version_symbol;

  if (module_version != NULL) {

    version_symbol = SymbolTable::new_symbol(module_version);

  } else {

    version_symbol = NULL;

  }

  // Obtain java.base's location

  const char* module_location = NULL;

  TempNewSymbol location_symbol = NULL;

  if (location != NULL) {

    module_location =

      java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(location));

    if (module_location != NULL) {

      location_symbol = SymbolTable::new_symbol(module_location);

    }

  }

  // Check that the packages are syntactically ok.

  GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);

  for (int x = 0; x < num_packages; x++) {

    const char *package_name = packages[x];

    if (!Modules::verify_package_name(package_name)) {

      THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

                err_msg("Invalid package name: %s for module: " JAVA_BASE_NAME, package_name));

    }

    Symbol* pkg_symbol = SymbolTable::new_symbol(package_name);

    pkg_list->append(pkg_symbol);

  }

  // Validate java_base's loader is the boot loader.

  oop loader = java_lang_Module::loader(module_handle());

  if (loader != NULL) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "Class loader must be the boot class loader");

  }

  Handle h_loader(THREAD, loader);

  // Ensure the boot loader's PackageEntryTable has been created

  PackageEntryTable* package_table = get_package_entry_table(h_loader);

  assert(pkg_list->length() == 0 || package_table != NULL, "Bad package_table");

  // Ensure java.base's ModuleEntry has been created

  assert(ModuleEntryTable::javabase_moduleEntry() != NULL, "No ModuleEntry for " JAVA_BASE_NAME);

  bool duplicate_javabase = false;

  {

    MutexLocker m1(Module_lock, THREAD);

    if (ModuleEntryTable::javabase_defined()) {

      duplicate_javabase = true;

    } else {

      // Verify that all java.base packages created during bootstrapping are in

      // pkg_list.  If any are not in pkg_list, than a non-java.base class was

      // loaded erroneously pre java.base module definition.

      package_table->verify_javabase_packages(pkg_list);

      // loop through and add any new packages for java.base

      for (int x = 0; x < pkg_list->length(); x++) {

        // Some of java.base's packages were added early in bootstrapping, ignore duplicates.

        package_table->locked_create_entry_if_not_exist(pkg_list->at(x),

                                                        ModuleEntryTable::javabase_moduleEntry());

        assert(package_table->locked_lookup_only(pkg_list->at(x)) != NULL,

               "Unable to create a " JAVA_BASE_NAME " package entry");

        // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of

        // the Symbol* that was created above for each package. The refcount was incremented

        // by SymbolTable::new_symbol and as well by the PackageEntry creation.

        pkg_list->at(x)->decrement_refcount();

      }

      // Finish defining java.base's ModuleEntry

      ModuleEntryTable::finalize_javabase(module_handle, version_symbol, location_symbol);

    }

  }

  if (duplicate_javabase) {

    THROW_MSG(vmSymbols::java_lang_InternalError(),

              "Module " JAVA_BASE_NAME " is already defined");

  }

  // Only the thread that actually defined the base module will get here,

  // so no locking is needed.

  // Patch any previously loaded class's module field with java.base's java.lang.Module.

  ModuleEntryTable::patch_javabase_entries(module_handle);

  log_info(module, load)(JAVA_BASE_NAME " location: %s",

                         module_location != NULL ? module_location : "NULL");

  log_debug(module)("define_javabase_module(): Definition of module: "

                    JAVA_BASE_NAME ", version: %s, location: %s, package #: %d",

                    module_version != NULL ? module_version : "NULL",

                    module_location != NULL ? module_location : "NULL",

                    pkg_list->length());

  // packages defined to java.base

  if (log_is_enabled(Trace, module)) {

    for (int x = 0; x < pkg_list->length(); x++) {

      log_trace(module)("define_javabase_module(): creation of package %s for module " JAVA_BASE_NAME,

                        (pkg_list->at(x))->as_C_string());

    }

  }

}

// Caller needs ResourceMark.

void throw_dup_pkg_exception(const char* module_name, PackageEntry* package, TRAPS) {

  const char* package_name = package->name()->as_C_string();

  if (package->module()->is_named()) {

    THROW_MSG(vmSymbols::java_lang_IllegalStateException(),

      err_msg("Package %s for module %s is already in another module, %s, defined to the class loader",

              package_name, module_name, package->module()->name()->as_C_string()));

  } else {

    THROW_MSG(vmSymbols::java_lang_IllegalStateException(),

      err_msg("Package %s for module %s is already in the unnamed module defined to the class loader",

              package_name, module_name));

  }

}

void Modules::define_module(jobject module, jboolean is_open, jstring version,

                            jstring location, const char* const* packages,

                            jsize num_packages, TRAPS) {

  ResourceMark rm(THREAD);

  if (module == NULL) {

    THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");

  }

  if (num_packages < 0) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "num_packages must be >= 0");

  }

  if (packages == NULL && num_packages > 0) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "num_packages should be zero if packages is null");

  }

  Handle module_handle(THREAD, JNIHandles::resolve(module));

  if (!java_lang_Module::is_instance(module_handle())) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "module is not an instance of type java.lang.Module");

  }

  char* module_name = get_module_name(module_handle(), CHECK);

  if (module_name == NULL) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "Module name cannot be null");

  }

  // Special handling of java.base definition

  if (strcmp(module_name, JAVA_BASE_NAME) == 0) {

    assert(is_open == JNI_FALSE, "java.base module cannot be open");

    define_javabase_module(module, version, location, packages, num_packages, CHECK);

    return;

  }

  const char* module_version = get_module_version(version);

  oop loader = java_lang_Module::loader(module_handle());

  // Make sure loader is not the jdk.internal.reflect.DelegatingClassLoader.

  if (!oopDesc::equals(loader, java_lang_ClassLoader::non_reflection_class_loader(loader))) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "Class loader is an invalid delegating class loader");

  }

  Handle h_loader = Handle(THREAD, loader);

  // define_module can be called during start-up, before the class loader's ClassLoaderData

  // has been created.  SystemDictionary::register_loader ensures creation, if needed.

  ClassLoaderData* loader_data = SystemDictionary::register_loader(h_loader);

  assert(loader_data != NULL, "class loader data shouldn't be null");

  // Check that the list of packages has no duplicates and that the

  // packages are syntactically ok.

  GrowableArray<Symbol*>* pkg_list = new GrowableArray<Symbol*>(num_packages);

  for (int x = 0; x < num_packages; x++) {

    const char* package_name = packages[x];

    if (!verify_package_name(package_name)) {

      THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

                err_msg("Invalid package name: %s for module: %s",

                        package_name, module_name));

    }

    // Only modules defined to either the boot or platform class loader, can define a "java/" package.

    if (!h_loader.is_null() &&

        !SystemDictionary::is_platform_class_loader(h_loader()) &&

        (strncmp(package_name, JAVAPKG, JAVAPKG_LEN) == 0 &&

          (package_name[JAVAPKG_LEN] == '/' || package_name[JAVAPKG_LEN] == '\0'))) {

      const char* class_loader_name = loader_data->loader_name_and_id();

      size_t pkg_len = strlen(package_name);

      char* pkg_name = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, pkg_len + 1);

      strncpy(pkg_name, package_name, pkg_len + 1);

      StringUtils::replace_no_expand(pkg_name, "/", ".");

      const char* msg_text1 = "Class loader (instance of): ";

      const char* msg_text2 = " tried to define prohibited package name: ";

      size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + pkg_len + 1;

      char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);

      jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, pkg_name);

      THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), message);

    }

    Symbol* pkg_symbol = SymbolTable::new_symbol(package_name);

    pkg_list->append(pkg_symbol);

  }

  ModuleEntryTable* module_table = get_module_entry_table(h_loader);

  assert(module_table != NULL, "module entry table shouldn't be null");

  // Create symbol* entry for module name.

  TempNewSymbol module_symbol = SymbolTable::new_symbol(module_name);

  bool dupl_modules = false;

  // Create symbol* entry for module version.

  TempNewSymbol version_symbol;

  if (module_version != NULL) {

    version_symbol = SymbolTable::new_symbol(module_version);

  } else {

    version_symbol = NULL;

  }

  // Create symbol* entry for module location.

  const char* module_location = NULL;

  TempNewSymbol location_symbol = NULL;

  if (location != NULL) {

    module_location =

      java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(location));

    if (module_location != NULL) {

      location_symbol = SymbolTable::new_symbol(module_location);

    }

  }

  PackageEntryTable* package_table = NULL;

  PackageEntry* existing_pkg = NULL;

  {

    MutexLocker ml(Module_lock, THREAD);

    if (num_packages > 0) {

      package_table = get_package_entry_table(h_loader);

      assert(package_table != NULL, "Missing package_table");

      // Check that none of the packages exist in the class loader's package table.

      for (int x = 0; x < pkg_list->length(); x++) {

        existing_pkg = package_table->locked_lookup_only(pkg_list->at(x));

        if (existing_pkg != NULL) {

          // This could be because the module was already defined.  If so,

          // report that error instead of the package error.

          if (module_table->lookup_only(module_symbol) != NULL) {

            dupl_modules = true;

          }

          break;

        }

      }

    }  // if (num_packages > 0)...

    // Add the module and its packages.

    if (!dupl_modules && existing_pkg == NULL) {

      if (module_table->lookup_only(module_symbol) == NULL) {

        // Create the entry for this module in the class loader's module entry table.

        ModuleEntry* module_entry = module_table->locked_create_entry(module_handle,

                                    (is_open == JNI_TRUE), module_symbol,

                                    version_symbol, location_symbol, loader_data);

        assert(module_entry != NULL, "module_entry creation failed");

        // Add the packages.

        assert(pkg_list->length() == 0 || package_table != NULL, "Bad package table");

        for (int y = 0; y < pkg_list->length(); y++) {

          package_table->locked_create_entry(pkg_list->at(y), module_entry);

          // Unable to have a GrowableArray of TempNewSymbol.  Must decrement the refcount of

          // the Symbol* that was created above for each package. The refcount was incremented

          // by SymbolTable::new_symbol and as well by the PackageEntry creation.

          pkg_list->at(y)->decrement_refcount();

        }

        // Store pointer to ModuleEntry record in java.lang.Module object.

        java_lang_Module::set_module_entry(module_handle(), module_entry);

      } else {

         dupl_modules = true;

      }

    }

  }  // Release the lock

  // any errors ?

  if (dupl_modules) {

     THROW_MSG(vmSymbols::java_lang_IllegalStateException(),

               err_msg("Module %s is already defined", module_name));

  } else if (existing_pkg != NULL) {

      throw_dup_pkg_exception(module_name, existing_pkg, CHECK);

  }

  log_info(module, load)("%s location: %s", module_name,

                         module_location != NULL ? module_location : "NULL");

  LogTarget(Debug, module) lt;

  if (lt.is_enabled()) {

    LogStream ls(lt);

    ls.print("define_module(): creation of module: %s, version: %s, location: %s, ",

                 module_name, module_version != NULL ? module_version : "NULL",

                 module_location != NULL ? module_location : "NULL");

    loader_data->print_value_on(&ls);

    ls.print_cr(", package #: %d", pkg_list->length());

    for (int y = 0; y < pkg_list->length(); y++) {

      log_trace(module)("define_module(): creation of package %s for module %s",

                        (pkg_list->at(y))->as_C_string(), module_name);

    }

  }

  // If the module is defined to the boot loader and an exploded build is being

  // used, prepend <java.home>/modules/modules_name to the system boot class path.

  if (loader == NULL && !ClassLoader::has_jrt_entry()) {

    ClassLoader::add_to_exploded_build_list(module_symbol, CHECK);

  }

}

void Modules::set_bootloader_unnamed_module(jobject module, TRAPS) {

  ResourceMark rm(THREAD);

  if (module == NULL) {

    THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");

  }

  Handle module_handle(THREAD, JNIHandles::resolve(module));

  if (!java_lang_Module::is_instance(module_handle())) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "module is not an instance of type java.lang.Module");

  }

  // Ensure that this is an unnamed module

  oop name = java_lang_Module::name(module_handle());

  if (name != NULL) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "boot loader's unnamed module's java.lang.Module has a name");

  }

  // Validate java_base's loader is the boot loader.

  oop loader = java_lang_Module::loader(module_handle());

  if (loader != NULL) {

    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

              "Class loader must be the boot class loader");

  }

  Handle h_loader(THREAD, loader);

  log_debug(module)("set_bootloader_unnamed_module(): recording unnamed module for boot loader");

  // Set java.lang.Module for the boot loader's unnamed module

  ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();

  ModuleEntry* unnamed_module = boot_loader_data->unnamed_module();

  assert(unnamed_module != NULL, "boot loader's unnamed ModuleEntry not defined");

  unnamed_module->set_module(boot_loader_data->add_handle(module_handle));

  // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.

  java_lang_Module::set_module_entry(module_handle(), unnamed_module);

}

void Modules::add_module_exports(jobject from_module, const char* package_name, jobject to_module, TRAPS) {

  if (package_name == NULL) {

    THROW_MSG(vmSymbols::java_lang_NullPointerException(),

              "package is null");