[PATCH] sys/types.h: Avoid bit-manipulation of signed values

[Nick Withers]

On Thu, 2015-11-12 at 13:57 +0100, Corinna Vinschen wrote:
> On Nov 12 15:14, Nick Withers wrote:
> > Sorry, let's try that again...
> > 
> > On Thu, 2015-11-12 at 15:11 +1100, Nick Withers wrote:
> > > Hi all,
> > > 
> > > The patch below attempts to resolve potential undefined behaviour
> > > in
> > > bit-manipulation in the FD_* macros, also clearing up the GCC
> > > warning
> > > "conversion to 'unsigned int' from 'int' may change the sign of
> > > the
> > > result" with -Wsign-conversion and an int FD parameter.
> 
> Sorry if I'm dense, but... all these macros (NBBY, FD_SETSIZE,
> howmany)
> are defined using int values, not unsigned int values, in glibc and
> everywhere else, e.g. X11/Xpoll.h, python2.7/pyport.h, etc.  I don't
> think we should use different definitions which potentially collide.

Righto, I'll submit a new version which does not modify these elements.

Can I kill howmany() entirely within sys/types.h or is it intended to
be exposed to userland after the header's included?

Should I provide a patch to the linux / winsup FD_ code?

> Corinna