This chapter used to describe Prolog utilities for generating glue code for the Foreign Language Interface (see Interface Predicates). As of SICStus 3.9, this is only supported using the splfr tool (see The Foreign Resource Linker).
You can invoke splfr (as well as spld) with the flags --verbose and --keep, in addition to the ordinary arguments. This way you can see what is going on and you can also access any generated files. The steps performed by splfr and the files generated will change between releases so you should avoid depending on it. If, for some reason, splfr is not suitable for your purposes you should contact SICStus Support.