Adding a borrow checker

[amir16yp]

What if the transpiler could improve memory safety (though not entirely remove manual memory management) by implementing a rust-esque borrow checker that would analyze the bytecode during transpilation and decide which declared variables are mutable or immutable?

[jonathanpeppers]

A Roslyn analyzer is probably the right place for this. At the C# level we still have semantic info (symbols, ref/out, escapes, captures, etc.), whereas IL where dotnes has current code has less information.

If someone’s up for it, an analyzer that enforces a “safe subset” (no ref escapes, no address-taking, no captured refs, etc.) would be a great first step: PRs welcome!

The analyzer MVP might just be to warn/error on things that don't work yet.

[jonathanpeppers]

Main has a Roslyn analyzer now, but we also have peek and poke for directly writing memory addresses -- no safety there!