test_swiftshader_utils.cc

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "flutter/testing/test_swiftshader_utils.h"
 
#include <cstdlib>
#include <mutex>
 
#include "flutter/fml/build_config.h"
#include "flutter/fml/file.h"
#include "flutter/fml/logging.h"
#include "flutter/fml/paths.h"
 
#if FML_OS_WIN
#include <Windows.h>
#endif  // FML_OS_WIN
 
namespace flutter::testing {
 
namespace {
 
void FindSwiftShaderICDAtKnownPaths() {
  static constexpr const char* kSwiftShaderICDJSON = "vk_swiftshader_icd.json";
  static constexpr const char* kVulkanICDFileNamesEnvVariableKey =
      "VK_ICD_FILENAMES";
  const auto executable_directory_path =
      fml::paths::GetExecutableDirectoryPath();
  FML_CHECK(executable_directory_path.first);
  auto icd_directory = executable_directory_path.second;
  if (icd_directory.ends_with("exe.unstripped")) {
    icd_directory = fml::paths::GetDirectoryName(icd_directory);
  }
  const auto icd_directory_fd = fml::OpenDirectory(icd_directory.c_str(), false,
                                                   fml::FilePermission::kRead);
  FML_CHECK(icd_directory_fd.is_valid());
  if (fml::FileExists(icd_directory_fd, kSwiftShaderICDJSON)) {
    const auto icd_path =
        fml::paths::JoinPaths({icd_directory, kSwiftShaderICDJSON});
#if FML_OS_WIN
    const auto success =
        ::SetEnvironmentVariableA(kVulkanICDFileNamesEnvVariableKey,  //
                                  icd_path.c_str()                    //
                                  ) != 0;
#else   // FML_OS_WIN
    const auto success = ::setenv(kVulkanICDFileNamesEnvVariableKey,  //
                                  icd_path.c_str(),                   //
                                  1  // overwrite
                                  ) == 0;
#endif  // FML_OS_WIN
    FML_CHECK(success)
        << "Could not set the environment variable to use SwiftShader.";
  } else {
    FML_CHECK(false)
        << "Was asked to use SwiftShader but could not find the installable "
           "client driver (ICD) for the locally built SwiftShader.";
  }
}
 
}  // namespace
 
void SetupSwiftshaderOnce(bool use_swiftshader) {
  static bool swiftshader_preference = false;
  static std::once_flag sOnceInitializer;
  std::call_once(sOnceInitializer, [use_swiftshader]() {
    if (use_swiftshader) {
      FindSwiftShaderICDAtKnownPaths();
      swiftshader_preference = use_swiftshader;
    }
  });
  FML_CHECK(swiftshader_preference == use_swiftshader)
      << "The option to use SwiftShader in a process can only be set once and "
         "may not be changed later.";
}
 
}  // namespace flutter::testing