[lsllc]

The Address Sanitizer (ASAN) in both clang and gcc is/are excellent:

https://github.com/google/sanitizers/wiki/addresssanitizer

I believe to integrate a custom allocator with ASAN, you need to look at the memory "poisoning" mechanisms:

https://github.com/google/sanitizers/wiki/AddressSanitizerMa...

[pjmlp]

It is also available on MVSC nowadays.

https://learn.microsoft.com/en-us/cpp/sanitizers/asan?view=m...

.NET team also makes use of it for the runtime parts,

https://devblogs.microsoft.com/cppblog/msvc-address-sanitize...