On 10/12/2018 3:54 PM, Stephen Hemminger wrote:
> On Fri, 12 Oct 2018 14:43:57 +0200
> Adrien Mazarguil <adrien.mazarg...@6wind.com> wrote:
>
>> On Fri, Oct 12, 2018 at 11:45:01AM +0100, Ferruh Yigit wrote:
>>> On 10/12/2018 11:42 AM, Ferruh Yigit wrote:
>>>> On 10/11/2018 6:59 PM, Stephen Hemminger wrote:
>>>>> @@ -161,8 +161,9 @@ extern "C" {
>>>>>
>>>>> extern int rte_eth_dev_logtype;
>>>>>
>>>>> -#define RTE_ETHDEV_LOG(level, ...) \
>>>>> - rte_log(RTE_LOG_ ## level, rte_eth_dev_logtype, "" __VA_ARGS__)
>>>>> +#define RTE_ETHDEV_LOG(level, fmt, ...) \
>>>>> + rte_log(RTE_LOG_ ## level, rte_eth_dev_logtype, \
>>>>> + "%s():" fmt, __func__, ## __VA_ARGS__)
>>>>
>>>> +1 to adding function name, but
>>>>
>>>> failsafe is giving build error [1] with clang because of ## usage [2],
>>>> that is
>>>> why I add this as ` "" __VA_ARGS__` at first place but you can't do this
>>>> trick
>>>> if __VA_ARGS__ used after fmt.
>>>>
>>>> I am not aware of a solution for this, __VA_OPT__(,) also didn't worked
>>>> with clang.
>>>
>>> +cc Adrien & Gaetan,
>>>
>>> I saw Adrien put some "workaround" to this for mlx5
>>
>> Yes, through RTE_FMT() (rte_common.h). Something like this:
>>
>> #define RTE_ETHDEV_LOG(level, fmt, ...) \
>> rte_log(RTE_LOG_ ## level, \
>> rte_eth_dev_logtype, \
>> "%s():" fmt, \
>> __func__, \
>> ## __VA_ARGS__)
>>
>> Can be rewritten like that:
>>
>> #define RTE_ETHDEV_LOG(level, ...) \
>> rte_log(RTE_LOG_ ## level, \
>> rte_eth_dev_logtype, \
>> RTE_FMT("%s():" RTE_FMT_HEAD(__VA_ARGS__,), \
>> __func__, \
>> RTE_FMT_TAIL(__VA_ARGS__,)))
>>
>> Although not too pretty and convenient, it does the job. In short:
>>
>> - Remove "fmt" argument from prototype.
>> - Enclose format string and its arguments in RTE_FMT().
>> - Replace "fmt" with RTE_FMT_HEAD(__VA_ARGS__,).
>> - Replace "## __VA_ARGS__" with RTE_FMT_TAIL(__VA_ARGS__,).
>> - Yes, trailing commas are mandatory in RTE_FMT_(HEAD|TAIL)().
>> - Note it quietly appends a dummy "%.0s" argument to the format string.
>>
>>>> [1]
>>>> .../build/include/rte_ethdev.h:166:26: error: token pasting of ',' and
>>>> __VA_ARGS__ is a GNU extension
>>>> [-Werror,-Wgnu-zero-variadic-macro-arguments]
>>>> "%s():" fmt, __func__, ## __VA_ARGS__)
>>>> ^
>>>>
>>>> [2]
>>>> This seems because of "-pedantic" argument driver uses, and other PMDs
>>>> using
>>>> "-pedantic", like mlx, will have same error although they are disable by
>>>> default and error not observed in default build.
>>>>
>>>
>>
>
> Since zero varadic macros is a GNU extension, maybe just adding GNU source?
I think `-pedantic` is preventing using extension whether we have `_GNU_SOURCE`
or not.
Gaetan,
Why we have `-pedantic` option enabled for failsafe?
