Comment by skissane

> Nope. Reason: the Fil-C runtime itself now relies on GC, and there's some functionality that only a GC can provide that has proven indispensable for porting some complex stuff (like CPython and Perl5).

What if there was a flag you could set on an allocation, “must be freed”. An app can set the “must be freed” flag on its allocations, meaning when the GC collects the allocation, it checks if free() has been called on it, and if it hasn’t, it logs a warning (or even panics), depending on process configuration flags. Meanwhile, internal allocations by the runtime won’t set that flag, so the GC will never panic/warn on collecting them.