vulkan-wsi-layer/util/helpers.hpp

/*
 * Copyright (c) 2021-2022 Arm Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/**
 * @file helpers.hpp
 *
 * @brief Contains common utility functions used across the project.
 */

#pragma once

#include <vulkan/vulkan.h>

/*
 * Conditional return statement. This allows functions to return early for
 * failing Vulkan commands with a terse syntax.
 *
 * Example usage:
 *
 * VkResult foo()
 * {
 *    TRY(vkCommand());
 *    return VK_SUCCESS;
 * }
 *
 * The above is equivalent to:
 *
 * VkResult foo()
 * {
 *    VkResult result = vkCommand();
 *    if (result != VK_SUCCESS)
 *    {
 *       return result;
 *    }
 *    return VK_SUCCESS;
 * }
 */
#define TRY(expression) \
   do \
   { \
      VkResult try_result = expression; \
      if (try_result != VK_SUCCESS) \
      { \
         return try_result; \
      } \
   } \
   while (0)

namespace util
{
template <typename T>
const T *find_extension(VkStructureType sType, const void *pNext)
{
   auto entry = reinterpret_cast<const VkBaseOutStructure *>(pNext);
   while (entry && entry->sType != sType)
   {
      entry = entry->pNext;
   }
   return reinterpret_cast<const T *>(entry);
}

template <typename T>
T *find_extension(VkStructureType sType, void *pNext)
{
   auto entry = reinterpret_cast<VkBaseOutStructure *>(pNext);
   while (entry && entry->sType != sType)
   {
      entry = entry->pNext;
   }
   return reinterpret_cast<T *>(entry);
}

class noncopyable
{
protected:
   noncopyable() = default;
   ~noncopyable() = default;

private:
   noncopyable(const noncopyable &) = delete;
   noncopyable& operator=(const noncopyable &) = delete;
};
} // namespace util