Best practices in portability have evolved since the 90s. I understand that portable C from that time was a nightmare, but things have changed a lot. As long a

Best practices in portability have evolved since the 90s. I understand that portable C from that time was a nightmare, but things have changed a lot. As long as you have a well defined portability layer, it doesn't really matter if it uses #ifdef or separate files (actually SQLite can be embedded as a single file, so it matters, but still). The important point of Spencer's paper was that portability shouldn't be a second thought. In fact it also mentions how to use #ifdef, not just when not to use it.