Re: [PATCH 1/2] introduce "banned function" list

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> Thanks for an interesting (and exotic) counter-point. For strcpy(), you
> always have to run strlen() anyway to know you're not going to overflow,
> so you might as well memcpy() at that point. But if you really are OK
> with truncation, then using strncpy() lets you copy while walking over
> the string only once, which is more efficient.  On the other hand,
> strncpy() fills out NULs to the end of the destination array, so you are
> paying an extra cost for small strings.
>
>> So I used strncpy() advisedly, and I ignore people running Coccinelle
>> scripts and blindly sending patches to "fix" ext4.

Given that strncpy() was invented in V7 days for specifically the
purpose of filling the filename field, it is not surprising at all
that it is the perfect tool for the same purpose in ext4 ;-)

> We don't have any remaining calls to strncpy() in Git, so this lets us
> punt on deciding if the ban is worth changing what's there. We can wait
> for somebody to decide they _really_ need strncpy, and we can discuss it
> then with a concrete case.

Yes, and the plan (or at least your plan) is to limit the banned
list to things that really has no reason to be used, the above
sounds like a good approach.