Re: [kvm-unit-tests PATCH] x86: setjmp: ignore clang's "-Wsomtimes-uninitialized" flag

[Bill Wendling <morbo@google.com>]

I sent out a separate patch. PTAL. :-)

On Tue, Sep 10, 2019 at 8:42 PM Bill Wendling <morbo@google.com> wrote:
>
> On Tue, Sep 10, 2019 at 12:59 PM Sean Christopherson
> <sean.j.christopherson@intel.com> wrote:
> >
> > On Tue, Sep 10, 2019 at 09:46:36AM -0700, Jim Mattson wrote:
> > > On Mon, Sep 9, 2019 at 2:10 PM Bill Wendling <morbo@google.com> wrote:
> > > >
> > > > Clang complains that "i" might be uninitialized in the "printf"
> > > > statement. This is a false negative, because it's set in the "if"
> > > > statement and then incremented in the loop created by the "longjmp".
> > > >
> > > > Signed-off-by: Bill Wendling <morbo@google.com>
> > > > ---
> > > >  x86/setjmp.c | 4 ++++
> > > >  1 file changed, 4 insertions(+)
> > > >
> > > > diff --git a/x86/setjmp.c b/x86/setjmp.c
> > > > index 976a632..cf9adcb 100644
> > > > --- a/x86/setjmp.c
> > > > +++ b/x86/setjmp.c
> > > > @@ -1,6 +1,10 @@
> > > >  #include "libcflat.h"
> > > >  #include "setjmp.h"
> > > >
> > > > +#ifdef __clang__
> > > > +#pragma clang diagnostic ignored "-Wsometimes-uninitialized"
> > > > +#endif
> > > > +
> > > >  int main(void)
> > > >  {
> > > >      volatile int i;
> > >
> > > Can we just add an initializer here instead?
> >
> > Doing so would also be a good opportunity to actually report on the
> > expected vs. actual value of 'i' instead of printing numbers that are
> > meaningless without diving into the code.
>
> My initial thought about adding an initializer was that the original
> test wanted to ensure that "i" was initialized after the "setjmp"
> call. But if we report the expected/actual value instead it wouldn't
> be an issue as we can set it to something not expected, etc... I'll
> create a patch.
>
> -bw