Re: [PATCH v2] eal/windows: resolve conversion and truncation warnings

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

On Thu, Mar 07, 2024 at 08:53:49PM +0000, Bruce Richardson wrote:
> On Thu, Mar 07, 2024 at 10:34:42AM -0800, Tyler Retzlaff wrote:
> > * Initialize const int NS_PER_SEC with an integer literal instead of
> >   double thereby avoiding implicit conversion from double to int.
> > 
> > * Cast the result of the expression assigned to timespec.tv_nsec to long.
> > 
> > Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> > Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> > ---
> > 
> > v2:
> >   * update commit message to correct misspelled timspec -> timespec,
> >     remove remarks about casting to long they were unnecessary.
> > 
> >  lib/eal/windows/include/rte_os_shim.h | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/lib/eal/windows/include/rte_os_shim.h b/lib/eal/windows/include/rte_os_shim.h
> > index eda8113..19b12e9 100644
> > --- a/lib/eal/windows/include/rte_os_shim.h
> > +++ b/lib/eal/windows/include/rte_os_shim.h
> > @@ -87,7 +87,7 @@
> >  static inline int
> >  rte_clock_gettime(clockid_t clock_id, struct timespec *tp)
> >  {
> > -	const int NS_PER_SEC = 1E9;
> > +	const int NS_PER_SEC = 1000000000;
> 
> Just for readability, and the immediate visibility of errors, could this be
> rewritten as (1000 * 1000 * 1000). That avoids us having to count the zeros
> to know that the number is correct.
> 
> BTW: is "int" still the best type to use for this value? Would it be better
> as a #define?

i think to save spot fixing i'm going to withdraw the series for now. i
need to come back later and deal with warnings from MSVC more
comprehensively anyway.

thanks folks!

> 
> /Bruce
> 
> >  	LARGE_INTEGER pf, pc;
> >  	LONGLONG nsec;
> >  
> > @@ -102,7 +102,7 @@
> >  
> >  		nsec = pc.QuadPart * NS_PER_SEC / pf.QuadPart;
> >  		tp->tv_sec = nsec / NS_PER_SEC;
> > -		tp->tv_nsec = nsec - tp->tv_sec * NS_PER_SEC;
> > +		tp->tv_nsec = (long)(nsec - tp->tv_sec * NS_PER_SEC);
> >  		return 0;
> >  	default:
> >  		return -1;
> > -- 
> > 1.8.3.1
> >