Set policies through CMake 3.9 to allow enabling IPO (#11560)

JosiahWI · web-flow · commit ef84c3b8b97b · 2021-08-23T22:13:47.000+02:00
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -1,5 +1,12 @@
 cmake_minimum_required(VERSION 3.5)
 
+# Set policies up to 3.9 since we want to enable the IPO option
+if(${CMAKE_VERSION} VERSION_LESS 3.9)
+	cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
+else()
+	cmake_policy(VERSION 3.9)
+endif()
+
 # This can be read from ${PROJECT_NAME} after project() is called
 project(minetest)
 set(PROJECT_NAME_CAPITALIZED "Minetest")
