Re: [Valgrind-users] helgrind suppressing on global variables

[Julian S. <js...@ac...>]

On Thursday 21 May 2009, Andy Howell wrote:
> Colin Miller wrote:
> > Andy Howell wrote:
> >> I have some code that uses the pre-processor to generate code to log
> >> messages:
> >>
> >> #define logDebug   if ( Log::minLevel <= Log::LVL_DEBUG )  Log::printLog
> >>
> >> Helgrind reports data races ultimately due to the global Log::minLevel.
> >> While technically this is a potential race condition, Log::minLevel is
> >> essentially a constant after startup.
> >>
> >> I tried to add suppressions for the mangled Log::printLog method,
> >> however because of the #define, helgrind reports the race on lines where
> >> LogDebug is used, not the Log::printLog method.
> >>
> >> Is there any way to add a suppression based on the global variable?
> >>
> >> Thanks,
> >>
> >> 	Andy
> >
> > Andy,
> > not an ideal solution, but could you do something like this
> >
> > static boolean logRequired(void)
> > {
> >    return (Log::minLevel <= Log::LVL_DEBUG);
> > }
> > #define logDebug if ( logRequired() ) Log::printLog
> >
> >
> > and then suppress the warning for logRequired()
> >
> >
> > Of course, you need to disable auto-inlining for logRequired()

Yes, I would strongly suggest adding __attribute__((noinline)) to the
declaration, if you want this to work (somewhat more) reliably in the
presence of inlining.

J