¿ is a good idea to compile C to C ?
I think this is a way to have cparser in miriad of small processors ( z8 encore, stm8, etc ), and assemblers and linkers are available.
A functional backend to emit ANSI C can be the best documented way a backend may have, libfirm has a TEMPLATE backend, but the way from this template to a working backend needs long learning wave. C programmers are used to read C code without docs, so make a new backend from this can be easier.