Fix garbage collection - Githubissues

rjnagel64 / lambdac

A simple functional language compiler that targets C

BSD 3-Clause "New" or "Revised" License

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Fix garbage collection #4

Closed rjnagel64 closed 2 years ago

rjnagel64 commented 2 years ago

There are two notable problems with the GC, that haven't yet manifested due to the test programs being tiny:

[ ] Tracing through allocations does not actually mark them as in use, so a GC will sweep live allocations
[ ] Tracing a cyclic data structure leads to an infinite loop and/or stack overflow, so recursive functions will trigger crashes.

AIUI, tricolor mark-sweep is supposed to be useful for this sort of thing.

rjnagel64 commented 2 years ago

Implementing fibonacci exposed the pitfalls of having a non-functional GC, so I replaced the old GC with one based on Crafting Interpreters. It works now.