Re: [PATCH v3 1/1] eal: add C++ include guard in generic/rte_vect.h

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

On Sat, Apr 06, 2024 at 07:30:38PM -0600, Ashish Sadanandan wrote:
> On Wed, Apr 3, 2024 at 8:52 AM Thomas Monjalon <thomas@monjalon.net> wrote:
> 
> > 02/04/2024 18:03, Ashish Sadanandan:
> > > Hi everyone,
> > > I've made the updates as suggested. Could someone please review the
> > latest
> > > patchset? Not sure if I followed the new patchset instructions correctly,
> > > I've always had trouble with that part.
> >
> > I remember we were discussing about aligning all files.
> > I was waiting for a patch applying the rule we discussed.
> >
> > I missed the part where people were volunteering me for additional work :)
> 
> The consensus seems to be that the extern "C" directives should only be in
> public headers, not private ones. Can you please tell me if there's an easy
> way to get a list of public headers?

build with driver_sdk_headers enabled.
run the meson install target.

all headers that are installed need the guard.

> 
> 
> > > On Sun, Mar 17, 2024 at 8:44 PM Ashish Sadanandan <
> > > ashish.sadanandan@gmail.com> wrote:
> > >
> > > > The header was missing the extern "C" directive which causes name
> > > > mangling of functions by C++ compilers, leading to linker errors
> > > > complaining of undefined references to these functions.
> > > >
> > > > Also updated the coding style contribution guideline with a new
> > > > "Language Linkage" section stating `extern "C"` block should be added
> > to
> > > > public headers.
> > > >
> > > > Fixes: 86c743cf9140 ("eal: define generic vector types")
> > > > Cc: nelio.laranjeiro@6wind.com
> > > > Cc: stable@dpdk.org
> > > >
> > > > Signed-off-by: Ashish Sadanandan <ashish.sadanandan@gmail.com>
> > > > ---
> > > >  .mailmap                                 |  2 +-
> > > >  doc/guides/contributing/coding_style.rst | 21 +++++++++++++++++++++
> > > >  lib/eal/include/generic/rte_vect.h       |  8 ++++++++
> > > >  3 files changed, 30 insertions(+), 1 deletion(-)
> > > >
> > > > --- a/doc/guides/contributing/coding_style.rst
> > > > +++ b/doc/guides/contributing/coding_style.rst
> > > > +Language Linkage
> > > > +~~~~~~~~~~~~~~~~
> > > > +
> > > > +Public headers should enclose all function and variable declarations
> > and
> > > > definitions in an ``extern "C"`` block to facilitate interoperability
> > with
> > > > C++.
> > > > +
> > > > +.. code-block:: c
> > > > +
> > > > +   #ifndef _FILE_H_
> > > > +   #define _FILE_H_
> > > > +
> > > > +   #ifdef __cplusplus
> > > > +   extern "C" {
> > > > +   #endif
> > > > +
> > > > +   /* Code */
> > > > +
> > > > +   #ifdef __cplusplus
> > > > +   }
> > > > +   #endif
> > > > +
> > > > +   #endif /* _FILE_H_ */
> >
> > This is not describing where the includes should be placed.
> >
> 
> Will address this along with the rest of the headers.
> 
> Regards,
> Ashish.