[PATCH 1/1] eal: add C++ include guard in generic/rte_vect.h

[Tyler Retzlaff]

On Wed, Mar 13, 2024 at 04:45:36PM -0700, Stephen Hemminger wrote:
> On Fri, 2 Feb 2024 13:58:19 -0700
> Ashish Sadanandan <ashish.sadanandan at gmail.com> wrote:
> 
> > > I think just having the extern "C" guard in all files is the safest choice,
> > > because it's immediately obvious in each and every file that it is correct.
> > > Taking the other option, to check any indirect include file you need to go
> > > finding what other files include it and check there that a) they have
> > > include guards and b) the include for the indirect header is contained
> > > within it.
> > >
> > > Adopting the policy of putting the guard in each and every header is also a
> > > lot easier to do basic automated sanity checks on. If the file ends in .h,
> > > we just use grep to quickly verify it's not missing the guards. [Naturally,
> > > we can do more complete checks than that if we want, but 99% percent of
> > > misses can be picked up by a grep for the 'extern "C"' bit]
> > >
> > > /Bruce
> > >  
> > 
> > 100% agree with Bruce. It's a valid ideological argument that private
> > headers
> > don't need such safeguards, but it's difficult to enforce and easy to break
> > during refactoring.
> > 
> > - Ashish
> 
> But splashing this across all the internal driver headers is bad idea.
> It should only apply to header files that exported in final package.

while we don't provide api/abi stability promises for driver headers we
do optionally install them with -Denable_driver_sdk=true.

the driver sdk allows drivers to be developed outside of the dpdk source
tree, many such drivers are explicitly authored in C++ and are outside of
the dpdk source tree because dpdk does not allow C++ drivers in tree.