r278264 - Reapply [Sema] Add sizeof diagnostics for bzero

[Joerg Sonnenberger via cfe-commits]

On Wed, Aug 10, 2016 at 02:36:01PM -0700, Bruno Cardoso Lopes wrote:
> Hi Joerg,
> 
> > Given that bzero is pretty much non-standard at this point, I strongly
> > dislike the approach of checking only the function name.
> 
> Thanks for the feedback. bzero it's widely used though, I think it's a
> usability win to perform a diagnostic here, despite bzero being
> non-standard.

Oh, I don't disagree that it is useful. Some projects still have a
ridiculous amount of non-standard bzero and bcmp invocations.

> 
> Is there any additional reason why you dislike it or additional checks
> you suggest? IIUC, Sema::CheckMemaccessArguments already checks if the
> number of arguments is the same and if they are indeed what they're
> supposed to be.

It checks the number of arguments, but that's about it. It doesn't for
example check that the first argument is a pointer.

> 
> If deprecation is the main issue here, shouldn't clang emit warnings
> to mention 'bzero' deprecation then?

It's not up to clang decide what the runtime environment provides or
deprecates. That said, bzero is no longer even part of SUSv4.

Joerg