public static IdeaPluginDescriptorImpl[] loadDescriptors(@Nullable StartupProgress progress) {
    if (ClassUtilCore.isLoadingOfExternalPluginsDisabled()) {
      return IdeaPluginDescriptorImpl.EMPTY_ARRAY;
    }

    final List<IdeaPluginDescriptorImpl> result = new ArrayList<IdeaPluginDescriptorImpl>();

    int pluginsCount =
        countPlugins(PathManager.getPluginsPath())
            + countPlugins(PathManager.getPreInstalledPluginsPath());
    loadDescriptors(PathManager.getPluginsPath(), result, progress, pluginsCount);
    Application application = ApplicationManager.getApplication();
    boolean fromSources = false;
    if (application == null || !application.isUnitTestMode()) {
      int size = result.size();
      loadDescriptors(PathManager.getPreInstalledPluginsPath(), result, progress, pluginsCount);
      fromSources = size == result.size();
    }

    loadDescriptorsFromProperty(result);

    loadDescriptorsFromClassPath(result, fromSources ? progress : null);

    IdeaPluginDescriptorImpl[] pluginDescriptors =
        result.toArray(new IdeaPluginDescriptorImpl[result.size()]);
    try {
      Arrays.sort(pluginDescriptors, new PluginDescriptorComparator(pluginDescriptors));
    } catch (Exception e) {
      prepareLoadingPluginsErrorMessage(
          IdeBundle.message("error.plugins.were.not.loaded", e.getMessage()));
      getLogger().info(e);
      return findCorePlugin(pluginDescriptors);
    }
    return pluginDescriptors;
  }
 public static void initClassLoader(
     @NotNull ClassLoader parentLoader, @NotNull IdeaPluginDescriptorImpl descriptor) {
   final List<File> classPath = descriptor.getClassPath();
   final ClassLoader loader =
       createPluginClassLoader(
           classPath.toArray(new File[classPath.size()]),
           new ClassLoader[] {parentLoader},
           descriptor);
   descriptor.setLoader(loader);
 }
  static ClassLoader[] getParentLoaders(
      Map<PluginId, ? extends IdeaPluginDescriptor> idToDescriptorMap, PluginId[] pluginIds) {
    if (isUnitTestMode()) return new ClassLoader[0];
    final List<ClassLoader> classLoaders = new ArrayList<ClassLoader>();
    for (final PluginId id : pluginIds) {
      IdeaPluginDescriptor pluginDescriptor = idToDescriptorMap.get(id);
      if (pluginDescriptor == null) {
        continue; // Might be an optional dependency
      }

      final ClassLoader loader = pluginDescriptor.getPluginClassLoader();
      if (loader == null) {
        getLogger().error("Plugin class loader should be initialized for plugin " + id);
      }
      classLoaders.add(loader);
    }
    return classLoaders.toArray(new ClassLoader[classLoaders.size()]);
  }
  static void initializePlugins(@Nullable StartupProgress progress) {
    configureExtensions();

    final IdeaPluginDescriptorImpl[] pluginDescriptors = loadDescriptors(progress);

    final Class callerClass = ReflectionUtil.findCallerClass(1);
    assert callerClass != null;
    final ClassLoader parentLoader = callerClass.getClassLoader();

    final List<IdeaPluginDescriptorImpl> result = new ArrayList<IdeaPluginDescriptorImpl>();
    final HashMap<String, String> disabledPluginNames = new HashMap<String, String>();
    for (IdeaPluginDescriptorImpl descriptor : pluginDescriptors) {
      if (descriptor.getPluginId().getIdString().equals(CORE_PLUGIN_ID)) {
        final List<String> modules = descriptor.getModules();
        if (modules != null) {
          ourAvailableModules.addAll(modules);
        }
      }

      if (!shouldSkipPlugin(descriptor, pluginDescriptors)) {
        result.add(descriptor);
      } else {
        descriptor.setEnabled(false);
        disabledPluginNames.put(descriptor.getPluginId().getIdString(), descriptor.getName());
        initClassLoader(parentLoader, descriptor);
      }
    }

    prepareLoadingPluginsErrorMessage(filterBadPlugins(result, disabledPluginNames));

    final Map<PluginId, IdeaPluginDescriptorImpl> idToDescriptorMap =
        new HashMap<PluginId, IdeaPluginDescriptorImpl>();
    for (final IdeaPluginDescriptorImpl descriptor : result) {
      idToDescriptorMap.put(descriptor.getPluginId(), descriptor);
    }

    final IdeaPluginDescriptor corePluginDescriptor =
        idToDescriptorMap.get(PluginId.getId(CORE_PLUGIN_ID));
    assert corePluginDescriptor != null
        : CORE_PLUGIN_ID
            + " not found; platform prefix is "
            + System.getProperty(PlatformUtilsCore.PLATFORM_PREFIX_KEY);
    for (IdeaPluginDescriptorImpl descriptor : result) {
      if (descriptor != corePluginDescriptor) {
        descriptor.insertDependency(corePluginDescriptor);
      }
    }

    mergeOptionalConfigs(idToDescriptorMap);

    // sort descriptors according to plugin dependencies
    Collections.sort(result, getPluginDescriptorComparator(idToDescriptorMap));

    for (int i = 0; i < result.size(); i++) {
      ourId2Index.put(result.get(i).getPluginId(), i);
    }

    int i = 0;
    for (final IdeaPluginDescriptorImpl pluginDescriptor : result) {
      if (pluginDescriptor.getPluginId().getIdString().equals(CORE_PLUGIN_ID)
          || pluginDescriptor.isUseCoreClassLoader()) {
        pluginDescriptor.setLoader(parentLoader);
      } else {
        final List<File> classPath = pluginDescriptor.getClassPath();
        final PluginId[] dependentPluginIds = pluginDescriptor.getDependentPluginIds();
        final ClassLoader[] parentLoaders = getParentLoaders(idToDescriptorMap, dependentPluginIds);

        final ClassLoader pluginClassLoader =
            createPluginClassLoader(
                classPath.toArray(new File[classPath.size()]),
                parentLoaders.length > 0 ? parentLoaders : new ClassLoader[] {parentLoader},
                pluginDescriptor);
        pluginDescriptor.setLoader(pluginClassLoader);
      }

      if (progress != null) {
        progress.showProgress(
            "", PLUGINS_PROGRESS_MAX_VALUE + (i++ / (float) result.size()) * 0.35f);
      }
    }

    registerExtensionPointsAndExtensions(Extensions.getRootArea(), result);
    Extensions.getRootArea()
        .getExtensionPoint(Extensions.AREA_LISTENER_EXTENSION_POINT)
        .registerExtension(
            new AreaListener() {
              @Override
              public void areaCreated(
                  @NotNull String areaClass, @NotNull AreaInstance areaInstance) {
                registerExtensionPointsAndExtensions(Extensions.getArea(areaInstance), result);
              }

              @Override
              public void areaDisposing(
                  @NotNull String areaClass, @NotNull AreaInstance areaInstance) {}
            });

    ourPlugins = pluginDescriptors;
  }