/*

* Copyright (c) 2015, 2016, 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 "classfile/classFileParser.hpp"

#include "classfile/classFileStream.hpp"

#include "classfile/classLoaderData.hpp"

#include "classfile/klassFactory.hpp"

#include "memory/resourceArea.hpp"

#include "prims/jvmtiEnvBase.hpp"

#include "trace/traceMacros.hpp"

static ClassFileStream* prologue(ClassFileStream* stream,

                                 Symbol* name,

                                 ClassLoaderData* loader_data,

                                 Handle protection_domain,

                                 JvmtiCachedClassFileData** cached_class_file,

                                 TRAPS) {

  assert(stream != NULL, "invariant");

  if (JvmtiExport::should_post_class_file_load_hook()) {

    assert(THREAD->is_Java_thread(), "must be a JavaThread");

    const JavaThread* jt = (JavaThread*)THREAD;

    Handle class_loader(THREAD, loader_data->class_loader());

    // Get the cached class file bytes (if any) from the class that

    // is being redefined or retransformed. We use jvmti_thread_state()

    // instead of JvmtiThreadState::state_for(jt) so we don't allocate

    // a JvmtiThreadState any earlier than necessary. This will help

    // avoid the bug described by 7126851.

    JvmtiThreadState* state = jt->jvmti_thread_state();

    if (state != NULL) {

      KlassHandle* h_class_being_redefined =

        state->get_class_being_redefined();

      if (h_class_being_redefined != NULL) {

        instanceKlassHandle ikh_class_being_redefined =

          instanceKlassHandle(THREAD, (*h_class_being_redefined)());

        *cached_class_file = ikh_class_being_redefined->get_cached_class_file();

      }

    }

    unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());

    unsigned char* end_ptr = ptr + stream->length();

    JvmtiExport::post_class_file_load_hook(name,

                                           class_loader,

                                           protection_domain,

                                           &ptr,

                                           &end_ptr,

                                           cached_class_file);

    if (ptr != stream->buffer()) {

      // JVMTI agent has modified class file data.

      // Set new class file stream using JVMTI agent modified class file data.

      stream = new ClassFileStream(ptr,

                                   end_ptr - ptr,

                                   stream->source(),

                                   stream->need_verify());

    }

  }

  return stream;

}

instanceKlassHandle KlassFactory::create_from_stream(ClassFileStream* stream,

                                                     Symbol* name,

                                                     ClassLoaderData* loader_data,

                                                     Handle protection_domain,

                                                     const Klass* host_klass,

                                                     GrowableArray<Handle>* cp_patches,

                                                     TempNewSymbol* parsed_name,

                                                     TRAPS) {

  assert(stream != NULL, "invariant");

  assert(loader_data != NULL, "invariant");

  assert(THREAD->is_Java_thread(), "must be a JavaThread");

  bool changed_by_loadhook = false;

  ResourceMark rm;

  HandleMark hm;

  JvmtiCachedClassFileData* cached_class_file = NULL;

  ClassFileStream* old_stream = stream;

  stream = prologue(stream,

                    name,

                    loader_data,

                    protection_domain,

                    &cached_class_file,

                    CHECK_NULL);

  ClassFileParser parser(stream,

                         name,

                         loader_data,

                         protection_domain,

                         parsed_name,

                         host_klass,

                         cp_patches,

                         ClassFileParser::BROADCAST, // publicity level

                         CHECK_NULL);

  instanceKlassHandle result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);

  assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");

  if (result.is_null()) {

    return NULL;

  }

  if (cached_class_file != NULL) {

    // JVMTI: we have an InstanceKlass now, tell it about the cached bytes

    result->set_cached_class_file(cached_class_file);

  }

  TRACE_KLASS_CREATION(result, parser, THREAD);

  return result;

}