From: Eric Sunshine <sunshine@sunshineco.com>
To: Jeff King <peff@peff.net>
Cc: Git List <git@vger.kernel.org>, Stefan Beller <sbeller@google.com>
Subject: Re: [PATCH 1/2] introduce "banned function" list
Date: Thu, 19 Jul 2018 17:59:47 -0400 [thread overview]
Message-ID: <CAPig+cTbvKZ6Ui_ib2g2Xqbv8zFwJp9idocbWaZLxj0Lpe+YBA@mail.gmail.com> (raw)
In-Reply-To: <20180719212700.GA13151@sigill.intra.peff.net>
On Thu, Jul 19, 2018 at 5:27 PM Jeff King <peff@peff.net> wrote:
> On Thu, Jul 19, 2018 at 05:11:15PM -0400, Eric Sunshine wrote:
> > On Thu, Jul 19, 2018 at 4:39 PM Jeff King <peff@peff.net> wrote:
> > > + * This header lists functions that have been banned from our code base,
> > > + * because they're too easy to misuse (and even if used correctly,
> > > + * complicate audits). Including this header turns them into compile-time
> > > + * errors.
> >
> > When the above talks about "including this header", the implication is
> > that it must be included _after_ the system header(s) which declare
> > the banned functions. I wonder if that requirement should be stated
> > here explicitly.
>
> Hmm, does it need to be? I had originally intended it to be included
> before, actually, though in the end I put it later.
> I guess it would yield declarations like strcpy_is_banned(), which would
> cause _different_ errors (probably link-time ones).
Yes, that's what I meant. You'd only get link-time errors if banned.h
was included before the system headers (assuming I'm thinking about
this correctly).
> > (Probably not worth a re-roll.)
>
> Yeah, I doubt it matters much either way, since the inclusion is done
> automatically in git-compat-util.h.
Exactly.
> I had also originally imagined this to be triggered via DEVELOPER=1,
> with something like "-include banned.h" in CFLAGS. But I think it
> probably is appropriate for everybody to run it, since it shouldn't
> cause any false positives or other compilation issues.
Agreed.
> The one I brainstormed (but forgot to mention) is that it might be
> possible for a platform to have strcpy as a macro already? In which case
> we'd need to #undef it or risk a compilation error (even if the macro
> isn't actually used).
I have some recollection (perhaps long outdated or just wrong) of
Microsoft headers spewing deprecation warnings about "unsafe"
functions. I don't know whether they did that by covering functions
with macros or by decorating the function with a deprecation attribute
or by some other mechanism, but such concern seems well-founded.
#undef'ing them might indeed be a very good preventative tactic.
next prev parent reply other threads:[~2018-07-19 22:00 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-19 20:33 [PATCH 0/2] fail compilation with strcpy Jeff King
2018-07-19 20:39 ` [PATCH 1/2] introduce "banned function" list Jeff King
2018-07-19 21:11 ` Eric Sunshine
2018-07-19 21:27 ` Jeff King
2018-07-19 21:59 ` Eric Sunshine [this message]
2018-07-20 0:55 ` Jeff King
2018-07-19 21:15 ` Stefan Beller
2018-07-19 21:32 ` Jeff King
2018-07-19 21:47 ` Stefan Beller
2018-07-20 0:54 ` Jeff King
2018-07-19 22:46 ` Junio C Hamano
2018-07-19 23:55 ` Randall S. Becker
2018-07-20 1:08 ` Jeff King
2018-07-20 1:12 ` Jeff King
2018-07-20 9:32 ` Junio C Hamano
2018-07-20 17:45 ` Jeff King
2018-07-20 13:22 ` Theodore Y. Ts'o
2018-07-20 17:56 ` Jeff King
2018-07-20 19:03 ` Junio C Hamano
2018-07-20 12:42 ` Derrick Stolee
2018-07-20 14:41 ` Duy Nguyen
2018-07-20 17:48 ` Elijah Newren
2018-07-20 18:04 ` Jeff King
2018-07-20 18:00 ` Jeff King
2018-07-19 20:39 ` [PATCH 2/2] banned.h: mark strncpy as banned Jeff King
2018-07-19 21:12 ` Ævar Arnfjörð Bjarmason
2018-07-19 21:33 ` Jeff King
2018-07-20 18:58 ` [PATCH 0/2] fail compilation with strcpy Junio C Hamano
2018-07-20 19:18 ` Jeff King
2018-07-20 21:50 ` Junio C Hamano
2018-07-24 9:23 ` [PATCH v2 0/4] " Jeff King
2018-07-24 9:26 ` [PATCH v2 1/4] automatically ban strcpy() Jeff King
2018-07-24 17:20 ` Eric Sunshine
2018-07-26 6:58 ` Jeff King
2018-07-26 7:21 ` [PATCH v3 " Jeff King
2018-07-26 17:33 ` Junio C Hamano
2018-07-27 8:08 ` Jeff King
2018-07-27 17:34 ` Junio C Hamano
2018-07-28 9:24 ` Jeff King
2018-07-24 9:26 ` [PATCH v2 2/4] banned.h: mark strcat() as banned Jeff King
2018-07-24 9:27 ` [PATCH v2 3/4] banned.h: mark sprintf() " Jeff King
2018-07-24 9:28 ` [PATCH v2 4/4] banned.h: mark strncpy() " Jeff King
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