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.
> >
>
--
Adrien Mazarguil
6WIND
