Re: [PATCH] rust: fmt: reject {:p} format specifier for raw pointers

["Danilo Krummrich" <dakr@kernel.org>]

On Tue Dec 23, 2025 at 7:41 AM CET, Miguel Ojeda wrote:
> Regarding the patch itself, ideally what we probably want is to do
> something similar to the C side, i.e. by default hash the pointers
> like C does, and then have an explicit way to request the real address
> when really needed.

Indeed, but I think the latter is even more important:

In C %p is commonly used for debugging when the actual address does not matter,
but a unique object needs to be identified (in quite a lot of cases to hunt down
memory bugs).

In Rust we should have quite fewer memory bugs to begin with (there may still be
ones in unsafe code, e.g. in abstractions) and we have built-in language
capabilities to easily derive debug prints for objects, which are more useful
then just a semi-unique identifier in a lot of cases.

So, what we are (mostly) left with I think are cases where we do want to print
the actual address temporarily for debug purposes, e.g. when interacting with
hardware (DMA memory, shared memory, etc.).