Suppose you have a very simple CMakeLists.txt
add_executable(silent T.cpp A.asm)
CMake will happily generate a C++ target for building silent, with T.cpp in it, but will silently drop any and all reference to A.asm, because it doesn't know what to do with the suffix.
Is there any way to get CMake to loudly complain about this source file it doesn't understand (to aid in porting a Makefile to CMake).