[dpdk-dev] [PATCH v4 25/27] eal: mark old naming as deprecated

[Burakov, Anatoly]

On 22-Jul-20 10:05 AM, Burakov, Anatoly wrote:
> On 20-Jul-20 7:51 PM, Stephen Hemminger wrote:
>> On Mon, 20 Jul 2020 13:32:27 +0100
>> "Burakov, Anatoly" <anatoly.burakov at intel.com> wrote:
>>
>>> On 18-Jul-20 3:22 AM, Stephen Hemminger wrote:
>>>> On Fri, 17 Jul 2020 16:21:37 +0100
>>>> "Burakov, Anatoly" <anatoly.burakov at intel.com> wrote:
>>>>> On 16-Jul-20 11:04 PM, Stephen Hemminger wrote:
>>>>>> On Thu, 16 Jul 2020 14:41:41 +0100
>>>>>> "Burakov, Anatoly" <anatoly.burakov at intel.com> wrote:
>>>>>>> On 15-Jul-20 9:29 PM, Stephen Hemminger wrote:
>>>>>>>> On Wed, 15 Jul 2020 14:28:17 +0100
>>>>>>>> "Burakov, Anatoly" <anatoly.burakov at intel.com> wrote:
>>>>>>>>>> -#define SKIP_MASTER    SKIP_INITIAL
>>>>>>>>>> -#define CALL_MASTER    CALL_INITIAL
>>>>>>>>>> +#define SKIP_MASTER _Pragma("GCC warning \"'SKIP_MASTER' is 
>>>>>>>>>> deprecated\"") SKIP_INITIAL
>>>>>>>>>> +#define CALL_MASTER _Pragma("GCC warning \"'CALL_MASTER' is 
>>>>>>>>>> deprecated\"") CALL_INITIAL
>>>>>>>>>
>>>>>>>>> Presumably this is a generic header, should we introduce 
>>>>>>>>> GCC-specific
>>>>>>>>> things there?
>>>>>>>>
>>>>>>>> It works with Clang as well. Likely ICC but don't have that.
>>>>>>>
>>>>>>> What about MSVC?
>>>>>>
>>>>>> _Pragma is C99 standard so MSVC know it.
>>>>>> MSVC should ignore any pragman it doesn't understand.
>>>>>>
>>>>>> There is a better pragma for deprecating keywords in MSVC, but GCC 
>>>>>> and Clang don't
>>>>>> understand it.
>>>>>
>>>>> Deprecating macros sounds like something we might want to do in the
>>>>> future, can't we put some macro into rte_common.h to address this? 
>>>>> e.g.
>>>>> something like
>>>>>
>>>>> #ifdef MSVC
>>>>> #define rte_deprecated_macro _msvc_pragma_whatever()
>>>>> #else
>>>>> #define rte_deprecated_macro _Pragma("GCC warning ...")
>>>>> #endif
>>>>>
>>>>> and use this macro here?
>>>>
>>>> It gets hard to do macro in a macro,
>>>
>>> I don't have a strong opinion on this, but IMO it's certainly better
>>> than having a compiler-specific things in an API header file :)
>>>
>>
>> I was hoping for macro volunteer?
>>
>> Something like:
>> #define RTE_DEPRECATED(foo) ...
>>
> 
> Oh, sure, apologies for not picking up on that :D
> 
> A bit on the ugly side, but should work:
> 
> #define __rte_deprecated_macro(val) (_Pragma("GCC warning \"'" #val "'\" 
> is deprecated\"") (val))
> 
> To be used as:
> 
> #define NEW __rte_deprecated_macro(OLD)
> 
> (I feel there could be confusion between __rte_deprecated and 
> RTE_DEPRECATED, so both for consistency and clarity, i believe 
> "__rte_deprecated_macro" would be a better name - however, no strong 
> opinion, RTE_DEPRECATED is fine by me as well)
> 

Sorry, realized that i've done it the other way around :D

Perhaps this one would be better:

#define __rte_deprecated_macro(old) _Pragma("GCC warning \"'" #old "'\" 
is deprecated\"")

...

#define OLD __rte_deprecated_macro(OLD) NEW

-- 
Thanks,
Anatoly