rtc_base/win/get_activation_factory.cc

/*
 *  Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "rtc_base/win/get_activation_factory.h"

#include <libloaderapi.h>
#include <roapi.h>

namespace {

FARPROC LoadComBaseFunction(const char* function_name) {
  static HMODULE const handle =
      ::LoadLibraryExW(L"combase.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
  return handle ? ::GetProcAddress(handle, function_name) : nullptr;
}

decltype(&::RoGetActivationFactory) GetRoGetActivationFactoryFunction() {
  static decltype(&::RoGetActivationFactory) const function =
      reinterpret_cast<decltype(&::RoGetActivationFactory)>(
          LoadComBaseFunction("RoGetActivationFactory"));
  return function;
}

}  // namespace

namespace webrtc {

bool ResolveCoreWinRTDelayload() {
  return GetRoGetActivationFactoryFunction() &&
         ResolveCoreWinRTStringDelayload();
}

HRESULT RoGetActivationFactoryProxy(HSTRING class_id,
                                    const IID& iid,
                                    void** out_factory) {
  auto get_factory_func = GetRoGetActivationFactoryFunction();
  if (!get_factory_func)
    return E_FAIL;
  return get_factory_func(class_id, iid, out_factory);
}

}  // namespace webrtc