Re: [PATCH] attr: avoid recursion when expanding attribute macros

From: Jeff King <peff@peff.net>
Date: Nov 12, 2025, 07:16 UTC
Message-ID: <20251112071651.GB431661@coredump.intra.peff.net>
In-Reply-To: <aRQvyvMq61syGT7_@pks.im>

On Wed, Nov 12, 2025 at 07:57:14AM +0100, Patrick Steinhardt wrote:

Show 11 quoted lines

> So personally I would've probably leaned into the direction of enforcing
> a hard limit. I don't see a reason why anybody would need more than a
> couple of recursions, it culls both compute and memory growth, and it
> allows us to have a proper error message in case the limit is busted.
> Furthermore, we can demonstrate right now that it wasn't possible to
> have unlimited recursion anyway, which makes it easier to put a new
> limit into place.
> 
> But following my above reasoning I think it's okay to turn this into
> iteration, as well, though, but I'd like to hear whether my train of
> thought matches yours.

Yeah, it does match mine. If I wanted to waste a bunch of CPU and memory on a hosting site, there are a lot easier ways to do that than with really long gitattributes.

I'm not at all opposed to putting in a hard limit on top. My general feeling is that it never hurts to convert recursion to iteration; it only gives us more options. I'm not planning to work on a hard limit myself, but if you want to, be my guest. :)

I think if we do (or even if we don't), it may also be reasonable to shrink the max attribute file size to 10MB or even smaller.

-Peff