Comment by azakai
2 hours ago
Zig does offer some amount of temporal memory safety.
Link: https://zig.guide/standard-library/allocators/
Text:
> The Zig standard library also has a general-purpose debug allocator. This is a safe allocator that can prevent double-free, use-after-free and can detect leaks.
For more detail, see:
https://github.com/ziglang/zig/issues/3180#issuecomment-5284...
I still don't think that does anything regarding use-after-frees, only double-frees.
Here's the code: https://codeberg.org/ziglang/zig/src/commit/e44e927d33d37c44...
The closest callout in the doc comment is:
>Never reuses memory addresses, making it easier for Zig to detect branch on undefined values in case of dangling pointers. This relies on the backing allocator to also not reuse addresses.
But it's not really clear what this means. "branch on undefined values" would I think indicate that maybe they're doing a fill pattern that the compiler can detect at runtime when dereferenced? But I don't see it in the `free` path. It's not clear if this is deterministic or not either.