+option(LLVM_FORCE_USE_OLD_TOOLCHAIN
+ "Set to ON if you want to force CMake to use a toolchain older than those supported by LLVM."
+ OFF)
+if(NOT LLVM_FORCE_USE_OLD_TOOLCHAIN)
+ if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+ if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)
+ message(FATAL_ERROR "Host GCC version must be at least 4.7!")
+ endif()
+ elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+ if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.1)
+ message(FATAL_ERROR "Host Clang version must be at least 3.1!")
+ endif()
+ elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+ if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 17.0)
+ message(FATAL_ERROR "Host Visual Studio must be at least 2012 (MSVC 17.0)")
+ endif()
+ endif()
+endif()
+