Fil-C adds capabilities and garbage, though it mentions performace costs of 1.5x - 5x. I would think the capabilties aspect of this language extension would be better addressed by hardware proposals (like CHERI) to prevent adding too much overhead to systems that are performance-critical.
Other memory safe implementations for C and C++ mentioned/proposed are TrapC (https://vimeo.com/1028578347) and Safe C++ (https://safecpp.org/draft.html).
Fil-C adds capabilities and garbage, though it mentions performace costs of 1.5x - 5x. I would think the capabilties aspect of this language extension would be better addressed by hardware proposals (like CHERI) to prevent adding too much overhead to systems that are performance-critical.
Edit: It also looks like the author could use help porting C programs to Fil-C, see https://news.ycombinator.com/item?id=42158296.