enable_language(C) add_library(empty SHARED empty.c) get_property(_isMultiConfig GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG) if(_isMultiConfig) list(GET CMAKE_CONFIGURATION_TYPES 0 FIRST_CONFIG) set(GENERATE_CONDITION CONDITION $) endif() file(GENERATE OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/test.txt" CONTENT "$" ${GENERATE_CONDITION} )