Is there any reason that we can’t just add flang-rt to LLVM_ENABLE_RUNTIMES by default if flang is in LLVM_ENABLE_PROJECTS, so that there’s no change for end users here, like we do for mlir already?
flang won’t actually work without the runtime so it seems that it’d be nice to add it automatically. I suppose there are some use cases that might want to build the runtimes separately and so don’t want flang-rt built when flang is but maybe we could add a DFLANG_ENABLE_FLANG_RT=Off flag to control this behaviour at that level?
I’m not fully opposed to having to add it to LLVM_ENABLE_RUNTIMES but it’d be nicer if -DLLVM_ENABLE_PROJECTS="flang" gave you a functional compiler on its own.