CMake/Tests/RunCMake/File_Generate/COMPILE_LANGUAGE-genex.cmake

enable_language(CXX C)

add_library(empty empty.cpp empty.c)
target_compile_options(empty
  PRIVATE LANG_IS_$<COMPILE_LANGUAGE>
)

file(GENERATE
  OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/opts-$<COMPILE_LANGUAGE>.txt
  CONTENT "$<TARGET_PROPERTY:empty,COMPILE_OPTIONS>\n"
)