The performance implications of this are pretty agreeable, on the order of 2x CPU time and 3-4x memory usage. Much better than, say, Valgrind, which uses a dynamic recompilation approach that adds on the order of 20x overhead.
Beautifully simple solution that robustly captures essentially all memory issues in C family programming languages.
I plan on implementing ASan for Hare soon, and we'll likely see a cproc implementation as well. /thread