Re: [dpdk-dev] [PATCH] eal: simplify RTE_PMD_DEBUG_TRACE

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 14 Dec 2018 13:20:07 -0800
Jeff Shaw <jeffrey.b.shaw@intel.com> wrote:

> On Fri, Dec 14, 2018 at 12:50:55PM -0800, Stephen Hemminger wrote:
> > Use rte_log directly, eliminating no longer used rte_pmd_dev_trace
> > function. This removes variable length array which is problem on
> > Windows and other compilers not doing C99.
> > 
> > Also, drop unused RTE_PROC_PRIMARY macros.
> > 
> > Reported-by: Jeff Shaw <jeffrey.b.shaw@intel.com>
> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> > ---
> >  lib/librte_eal/common/include/rte_dev.h | 43 ++-----------------------
> >  1 file changed, 3 insertions(+), 40 deletions(-)
> > 
> > diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/common/include/rte_dev.h
> > index a9724dc9181c..e496da440028 100644
> > --- a/lib/librte_eal/common/include/rte_dev.h
> > +++ b/lib/librte_eal/common/include/rte_dev.h
> > @@ -43,54 +43,17 @@ typedef void (*rte_dev_event_cb_fn)(const char *device_name,
> >  					enum rte_dev_event_type event,
> >  					void *cb_arg);
> >  
> > -__attribute__((format(printf, 2, 0)))
> > -static inline void
> > -rte_pmd_debug_trace(const char *func_name, const char *fmt, ...)
> > -{
> > -	va_list ap;
> > -
> > -	va_start(ap, fmt);
> > -
> > -	{
> > -		char buffer[vsnprintf(NULL, 0, fmt, ap) + 1];
> > -
> > -		va_end(ap);
> > -
> > -		va_start(ap, fmt);
> > -		vsnprintf(buffer, sizeof(buffer), fmt, ap);
> > -		va_end(ap);
> > -
> > -		rte_log(RTE_LOG_ERR, RTE_LOGTYPE_PMD, "%s: %s",
> > -			func_name, buffer);
> > -	}
> > -}
> > -  
> 
> Will this break applications that try to use this function? Because it is not
> a documented function, is there no guarantee it will be present?

It shouldn't be visible as part of EAL. Any code that was built that had
old MACRO would still run (ABI compatible) because it was inline.