jdk

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/*
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 * Copyright (c) 2021, 2024, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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#include "precompiled.hpp"
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#include "cds/cds_globals.hpp"
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#include "cds/classListWriter.hpp"
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#include "cds/lambdaFormInvokers.inline.hpp"
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#include "classfile/classFileStream.hpp"
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#include "classfile/classLoader.hpp"
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#include "classfile/classLoaderData.hpp"
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#include "classfile/classLoaderDataGraph.hpp"
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#include "classfile/moduleEntry.hpp"
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#include "classfile/systemDictionaryShared.hpp"
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#include "memory/resourceArea.hpp"
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#include "oops/constantPool.inline.hpp"
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#include "oops/instanceKlass.hpp"
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#include "runtime/mutexLocker.hpp"
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fileStream* ClassListWriter::_classlist_file = nullptr;
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void ClassListWriter::init() {
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  // For -XX:DumpLoadedClassList=<file> option
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  if (DumpLoadedClassList != nullptr) {
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    const char* list_name = make_log_name(DumpLoadedClassList, nullptr);
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    _classlist_file = new(mtInternal)
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                         fileStream(list_name);
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    _classlist_file->print_cr("# NOTE: Do not modify this file.");
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    _classlist_file->print_cr("#");
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    _classlist_file->print_cr("# This file is generated via the -XX:DumpLoadedClassList=<class_list_file> option");
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    _classlist_file->print_cr("# and is used at CDS archive dump time (see -Xshare:dump).");
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    _classlist_file->print_cr("#");
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    FREE_C_HEAP_ARRAY(char, list_name);
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  }
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}
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void ClassListWriter::write(const InstanceKlass* k, const ClassFileStream* cfs) {
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  assert(is_enabled(), "must be");
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  if (!ClassLoader::has_jrt_entry()) {
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    log_warning(cds)("DumpLoadedClassList and CDS are not supported in exploded build");
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    DumpLoadedClassList = nullptr;
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    return;
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  }
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  ClassListWriter w;
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  write_to_stream(k, w.stream(), cfs);
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}
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class ClassListWriter::IDTable : public ResourceHashtable<
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  const InstanceKlass*, int,
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  15889, // prime number
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  AnyObj::C_HEAP> {};
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ClassListWriter::IDTable* ClassListWriter::_id_table = nullptr;
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int ClassListWriter::_total_ids = 0;
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int ClassListWriter::get_id(const InstanceKlass* k) {
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  assert_locked();
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  if (_id_table == nullptr) {
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    _id_table = new (mtClass)IDTable();
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  }
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  bool created;
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  int* v = _id_table->put_if_absent(k, &created);
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  if (created) {
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    *v = _total_ids++;
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  }
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  return *v;
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}
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bool ClassListWriter::has_id(const InstanceKlass* k) {
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  assert_locked();
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  if (_id_table != nullptr) {
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    return _id_table->get(k) != nullptr;
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  } else {
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    return false;
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  }
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}
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void ClassListWriter::handle_class_unloading(const InstanceKlass* klass) {
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  assert_locked();
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  if (_id_table != nullptr) {
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    _id_table->remove(klass);
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  }
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}
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void ClassListWriter::write_to_stream(const InstanceKlass* k, outputStream* stream, const ClassFileStream* cfs) {
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  assert_locked();
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  ClassLoaderData* loader_data = k->class_loader_data();
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  bool is_builtin_loader = SystemDictionaryShared::is_builtin_loader(loader_data);
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  if (!is_builtin_loader) {
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    // class may be loaded from shared archive
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    if (!k->is_shared()) {
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      if (cfs == nullptr || cfs->source() == nullptr) {
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        // CDS static dump only handles unregistered class with known source.
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        return;
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      }
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      if (strncmp(cfs->source(), "file:", 5) != 0) {
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        return;
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      }
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    } else {
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      // Shared unregistered classes are skipped since their real source are not recorded in shared space.
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      return;
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    }
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    if (!SystemDictionaryShared::add_unregistered_class(Thread::current(), (InstanceKlass*)k)) {
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      return;
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    }
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  }
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  // filter out java/lang/invoke/BoundMethodHandle$Species...
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  if (cfs != nullptr && cfs->source() != nullptr && strcmp(cfs->source(), "_ClassSpecializer_generateConcreteSpeciesCode") == 0) {
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    return;
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  }
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  {
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    InstanceKlass* super = k->java_super();
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    if (super != nullptr && !has_id(super)) {
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      return;
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    }
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    Array<InstanceKlass*>* interfaces = k->local_interfaces();
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    int len = interfaces->length();
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    for (int i = 0; i < len; i++) {
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      InstanceKlass* intf = interfaces->at(i);
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      if (!has_id(intf)) {
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        return;
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      }
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    }
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  }
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  if (k->is_hidden()) {
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    return;
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  }
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  if (k->module()->is_patched()) {
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    return;
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  }
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  ResourceMark rm;
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  stream->print("%s id: %d", k->name()->as_C_string(), get_id(k));
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  if (!is_builtin_loader) {
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    InstanceKlass* super = k->java_super();
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    assert(super != nullptr, "must be");
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    stream->print(" super: %d", get_id(super));
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    Array<InstanceKlass*>* interfaces = k->local_interfaces();
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    int len = interfaces->length();
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    if (len > 0) {
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      stream->print(" interfaces:");
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      for (int i = 0; i < len; i++) {
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        InstanceKlass* intf = interfaces->at(i);
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        stream->print(" %d", get_id(intf));
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      }
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    }
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#ifdef _WINDOWS
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    // "file:/C:/dir/foo.jar" -> "C:/dir/foo.jar"
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    stream->print(" source: %s", cfs->source() + 6);
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#else
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    // "file:/dir/foo.jar" -> "/dir/foo.jar"
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    stream->print(" source: %s", cfs->source() + 5);
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#endif
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  }
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  stream->cr();
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  stream->flush();
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}
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void ClassListWriter::delete_classlist() {
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  if (_classlist_file != nullptr) {
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    delete _classlist_file;
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  }
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}
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class ClassListWriter::WriteResolveConstantsCLDClosure : public CLDClosure {
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public:
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  void do_cld(ClassLoaderData* cld) {
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    for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
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      if (klass->is_instance_klass()) {
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        InstanceKlass* ik = InstanceKlass::cast(klass);
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        write_resolved_constants_for(ik);
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      }
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    }
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  }
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};
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void ClassListWriter::write_resolved_constants() {
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  if (!is_enabled()) {
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    return;
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  }
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  MutexLocker lock(ClassLoaderDataGraph_lock);
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  MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
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  WriteResolveConstantsCLDClosure closure;
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  ClassLoaderDataGraph::loaded_cld_do(&closure);
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}
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void ClassListWriter::write_resolved_constants_for(InstanceKlass* ik) {
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  if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data()) ||
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      ik->is_hidden()) {
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    return;
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  }
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  if (LambdaFormInvokers::may_be_regenerated_class(ik->name())) {
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    return;
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  }
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  if (ik->name()->equals("jdk/internal/module/SystemModules$all")) {
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    // This class is regenerated during JDK build process, so the classlist
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    // may not match the version that's in the real jdk image.
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    return;
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  }
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  if (!has_id(ik)) { // do not resolve CP for classes loaded by custom loaders.
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    return;
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  }
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  ResourceMark rm;
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  ConstantPool* cp = ik->constants();
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  GrowableArray<bool> list(cp->length(), cp->length(), false);
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  bool print = false;
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  for (int cp_index = 1; cp_index < cp->length(); cp_index++) { // Index 0 is unused
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    switch (cp->tag_at(cp_index).value()) {
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    case JVM_CONSTANT_Class:
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      {
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        Klass* k = cp->resolved_klass_at(cp_index);
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        if (k->is_instance_klass()) {
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          list.at_put(cp_index, true);
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          print = true;
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        }
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      }
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      break;
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    }
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  }
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  if (cp->cache() != nullptr) {
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    Array<ResolvedFieldEntry>* field_entries = cp->cache()->resolved_field_entries();
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    if (field_entries != nullptr) {
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      for (int i = 0; i < field_entries->length(); i++) {
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        ResolvedFieldEntry* rfe = field_entries->adr_at(i);
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        if (rfe->is_resolved(Bytecodes::_getfield) ||
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            rfe->is_resolved(Bytecodes::_putfield)) {
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          list.at_put(rfe->constant_pool_index(), true);
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          print = true;
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        }
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      }
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    }
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    Array<ResolvedMethodEntry>* method_entries = cp->cache()->resolved_method_entries();
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    if (method_entries != nullptr) {
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      for (int i = 0; i < method_entries->length(); i++) {
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        ResolvedMethodEntry* rme = method_entries->adr_at(i);
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        if (rme->is_resolved(Bytecodes::_invokevirtual) ||
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            rme->is_resolved(Bytecodes::_invokespecial) ||
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            rme->is_resolved(Bytecodes::_invokeinterface)) {
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          list.at_put(rme->constant_pool_index(), true);
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          print = true;
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        }
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      }
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    }
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  }
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  if (print) {
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    outputStream* stream = _classlist_file;
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    stream->print("@cp %s", ik->name()->as_C_string());
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    for (int i = 0; i < list.length(); i++) {
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      if (list.at(i)) {
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        constantTag cp_tag = cp->tag_at(i).value();
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        assert(cp_tag.value() == JVM_CONSTANT_Class ||
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               cp_tag.value() == JVM_CONSTANT_Fieldref ||
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               cp_tag.value() == JVM_CONSTANT_Methodref||
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               cp_tag.value() == JVM_CONSTANT_InterfaceMethodref, "sanity");
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        stream->print(" %d", i);
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      }
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    }
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    stream->cr();
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  }
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}
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