optional cmake 3.11

CMakeLists.txt

@@ -2,7 +2,7 @@
 MESSAGE(STATUS "Starting WOLF CMakeLists ...")
 
 # Pre-requisites about cmake itself
-CMAKE_MINIMUM_REQUIRED(VERSION 3.16)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.10)
 
 if(COMMAND cmake_policy)
   cmake_policy(SET CMP0005 NEW)

test/gtest/CMakeLists.txt

-include(FetchContent)
-FetchContent_Declare(
-  googletest
-  GIT_REPOSITORY https://github.com/google/googletest.git 
-  GIT_TAG main)
-FetchContent_MakeAvailable(googletest)
+if(${CMAKE_VERSION} VERSION_LESS "3.11.0") 
+  message("CMake version less than 3.11.0")
 
+  # Enable ExternalProject CMake module
+  include(ExternalProject)
 
+  set(GTEST_FORCE_SHARED_CRT ON)
+  set(GTEST_DISABLE_PTHREADS OFF)
+
+  # For some reason I need to disable PTHREADS
+  # with g++ (Ubuntu 4.9.3-8ubuntu2~14.04) 4.9.3
+  # This is a known issue for MinGW :
+  # https://github.com/google/shaderc/pull/174
+  #if(MINGW)
+      set(GTEST_DISABLE_PTHREADS ON)
+  #endif()
+
+  # Download GoogleTest
+  ExternalProject_Add(googletest
+      GIT_REPOSITORY https://github.com/google/googletest.git
+      GIT_TAG        v1.8.x
+      # TIMEOUT 1 # We'll try this
+      CMAKE_ARGS -DCMAKE_ARCHIVE_OUTPUT_DIRECTORY_DEBUG:PATH=DebugLibs
+      -DCMAKE_ARCHIVE_OUTPUT_DIRECTORY_RELEASE:PATH=ReleaseLibs
+      -DCMAKE_CXX_FLAGS=${MSVC_COMPILER_DEFS}
+      -Dgtest_force_shared_crt=${GTEST_FORCE_SHARED_CRT}
+      -Dgtest_disable_pthreads=${GTEST_DISABLE_PTHREADS}
+      -DBUILD_GTEST=ON
+      PREFIX "${CMAKE_CURRENT_BINARY_DIR}"
+      # Disable install step
+      INSTALL_COMMAND ""
+      UPDATE_DISCONNECTED 1 # 1: do not update googletest; 0: update googletest via github
+  )
+
+  # Get GTest source and binary directories from CMake project
+
+  # Specify include dir
+  ExternalProject_Get_Property(googletest source_dir)
+  set(GTEST_INCLUDE_DIRS ${source_dir}/googletest/include PARENT_SCOPE)
+
+  # Specify MainTest's link libraries
+  ExternalProject_Get_Property(googletest binary_dir)
+  set(GTEST_LIBS_DIR ${binary_dir}/googlemock/gtest PARENT_SCOPE)
+
+  # Create a libgtest target to be used as a dependency by test programs
+  add_library(libgtest IMPORTED STATIC GLOBAL)
+  add_dependencies(libgtest googletest)
+
+  # Set libgtest properties
+  set_target_properties(libgtest PROPERTIES
+      "IMPORTED_LOCATION" "${binary_dir}/googlemock/gtest/libgtest.a"
+      "IMPORTED_LINK_INTERFACE_LIBRARIES" "${CMAKE_THREAD_LIBS_INIT}"
+  )
+
+else()
+
+  message("CMake version equal or greater than 3.11.0")
+
+  include(FetchContent)
+
+  FetchContent_Declare(
+    googletest
+    GIT_REPOSITORY https://github.com/google/googletest.git 
+    GIT_TAG main)
+
+  FetchContent_MakeAvailable(googletest)
+    
+endif()
+  
 function(wolf_add_gtest target)
   add_executable(${target} ${ARGN})
   target_link_libraries(${target}  gtest_main)
   add_test(NAME ${target} COMMAND ${target})
-endfunction()
-
+endfunction()
\ No newline at end of file