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Subject: Re: [PATCH iproute2] iproute: make clang happy
Date: Tue, 21 Aug 2018 09:19:46 -0700
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Cc: Mahesh Bandewar <mahesh@bandewar.net>,
        netdev <netdev@vger.kernel.org>
To: Stephen Hemminger <stephen@networkplumber.org>
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On Mon, Aug 20, 2018 at 5:52 PM, Stephen Hemminger
<stephen@networkplumber.org> wrote:
> On Mon, 20 Aug 2018 16:44:28 -0700
> Mahesh Bandewar (=E0=A4=AE=E0=A4=B9=E0=A5=87=E0=A4=B6 =E0=A4=AC=E0=A4=82=
=E0=A4=A1=E0=A5=87=E0=A4=B5=E0=A4=BE=E0=A4=B0) <maheshb@google.com> wrote:
>
>> On Mon, Aug 20, 2018 at 4:38 PM, Mahesh Bandewar (=E0=A4=AE=E0=A4=B9=E0=
=A5=87=E0=A4=B6 =E0=A4=AC=E0=A4=82=E0=A4=A1=E0=A5=87=E0=A4=B5=E0=A4=BE=E0=
=A4=B0)
>> <maheshb@google.com> wrote:
>> > On Mon, Aug 20, 2018 at 3:52 PM, Stephen Hemminger
>> > <stephen@networkplumber.org> wrote:
>> >> On Mon, 20 Aug 2018 14:42:15 -0700
>> >> Mahesh Bandewar <mahesh@bandewar.net> wrote:
>> >>
>> >>> diff --git a/tc/m_ematch.c b/tc/m_ematch.c
>> >>> index ace4b3dd738b..a524b520b276 100644
>> >>> --- a/tc/m_ematch.c
>> >>> +++ b/tc/m_ematch.c
>> >>> @@ -277,6 +277,7 @@ static int flatten_tree(struct ematch *head, str=
uct ematch *tree)
>> >>>       return count;
>> >>>  }
>> >>>
>> >>> +__attribute__((format(printf, 5, 6)))
>> >>>  int em_parse_error(int err, struct bstr *args, struct bstr *carg,
>> >>>                  struct ematch_util *e, char *fmt, ...)
>> >>
>> >> I think the printf attribute needs to go on the function prototype
>> >> here:
>> >> tc/m_ematch.h:extern int em_parse_error(int err, struct bstr *args, s=
truct bstr *carg,
>> >>
>> > The attributes are attached to the definitions only and not prototype
>> > declarations. Please see the definition/declaration for jsonw_printf()
>> > in the same patch.
>> I take that back. Seems like it's fine either way.
>
> The reason to put the attributes in the .h file is that then the compiler
> can test for misuse in other files.  For example if em_parse_error had
> a bad format in em_u32.c, then the warning would not happen unless
> the attribute was on the function prototype.
>
correct, will take care in v2