function (disallow_intree_builds) # Adapted from LLVM's toplevel CMakeLists.txt file if( CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR AND NOT MSVC_IDE ) message(FATAL_ERROR " In-source builds are not allowed. CMake would overwrite the makefiles distributed with utf8proc. Please create a directory and run cmake from there. Building in a subdirectory is fine, e.g.: mkdir build cd build cmake .. This process created the file `CMakeCache.txt' and the directory `CMakeFiles'. Please delete them. ") endif() endfunction()