Check automatically if we have std::filesystem.

CMakeLists.txt

@@ -9,7 +9,6 @@ cmake_minimum_required(VERSION 3.18)
 project(gmsh_gpu_dg)
 include(CheckLanguage)
 
-
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CUDA_ARCHITECTURES 35 70)
@@ -20,6 +19,8 @@ set (CMAKE_MODULE_PATH
      ${CMAKE_MODULE_PATH}
      ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 
+set(CXX_LANGUAGE_FEATURES_TESTS_DIR "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+
 if(NOT DEFINED HIP_PATH)
     if(NOT DEFINED ENV{HIP_PATH})
         set(HIP_PATH "/opt/rocm/hip" CACHE PATH "Path to which HIP has been installed")
@@ -29,6 +30,11 @@ if(NOT DEFINED HIP_PATH)
 endif()
 set(CMAKE_MODULE_PATH "${HIP_PATH}/cmake" ${CMAKE_MODULE_PATH})
 
+try_compile(CXX_FEATURE_STD_FILESYSTEM ${CMAKE_BINARY_DIR} "${CXX_LANGUAGE_FEATURES_TESTS_DIR}/check_std_filesystem.cpp")
+if (NOT CXX_FEATURE_STD_FILESYSTEM)
+    add_definitions(-DDONT_USE_STD_FILESYSTEM)
+endif()
+
 if (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
     cmake_host_system_information(RESULT OSVER QUERY OS_RELEASE)
     if (OSVER VERSION_LESS "10.15")
@@ -154,11 +160,6 @@ if (OPT_ENABLE_GPU_SOLVER)
         endif()
 
     endif()
-
-    option(OPT_BLOCKED_GPU_KERNELS "Use blocked kernels on GPU (DO NOT USE)" OFF)
-    if (OPT_BLOCKED_GPU_KERNELS)
-        add_definitions(-DUSE_BLOCKED_GPU_KERNELS)
-    endif()
 endif()
 
 if (OPT_ENABLE_GPU_SOLVER)