Hi Ömer, See e.g. `lowerSafeForeignCall` and `blockCode`
which set the field with `Just`. The former seems to be related with foreign calls so perhaps try compiling a FFI package.
I tried compiling a module with a `foreign import ccall safe` declaration, yet the output raw Cmm still doesn't use `cml_cont`. `CmmLayoutStack` uses that field
for code generation (I don't understand the details yet).
Thanks for pointing that out, I'll check its implementation. I also found another evidence of the field not used by codegens: in `PprC` which is used by unregisterised builds, only the `cml_target` field is used. So for now I assume that the assertion of `cml_cont = Nothing` holds for final Cmm output, and backend writers need not be concerned with it. Regards, Shao Cheng