Re: [dpdk-dev] [dpdk-stable] [PATCH v2] ethdev: missing typecast causes C++ build error

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 16 Apr 2019 16:46:14 +0000
"Ananyev, Konstantin" <konstantin.ananyev@intel.com> wrote:

> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Andrew Rybchenko
> > Sent: Tuesday, April 16, 2019 5:40 PM
> > To: Yigit, Ferruh <ferruh.yigit@intel.com>; David Christensen <drc@linux.vnet.ibm.com>; thomas@monjalon.net
> > Cc: dev@dpdk.org; radhika.chirra@ibm.com; stable@dpdk.org
> > Subject: Re: [dpdk-dev] [dpdk-stable] [PATCH v2] ethdev: missing typecast causes C++ build error
> > 
> > On 4/16/19 7:31 PM, Ferruh Yigit wrote:  
> > > On 4/10/2019 10:36 PM, David Christensen wrote:  
> > >> The function eth_dev_pci_specific_init is missing a typecast to
> > >> (struct rte_pci_device *) for the input argument bus_device.
> > >> This causes build issues in the GNU C++ compiler.
> > >>
> > >> [CXX]       g++ -o utils/pcap_handle.o -c utils/pcap_handle.cc -g3·
> > >> -ggdb3 -mcpu=native -mtune=native -isystem·
> > >> /home/rchirra/gen/io/ppc64include -std=gnu++11 -flax-vector-conversions·
> > >> -Werror -isystem /home/rchirra/gen/io
> > >>
> > >> In file included from drivers/pmd.cc:7:0:
> > >> /home/rchirra/gen/io/deps/dpdk/build/include/rte_ethdev_pci.h:
> > >> In function ‘int eth_dev_pci_specific_init(rte_eth_dev*, void*)’:
> > >> /home/rchirra/gen/io/deps/dpdk/build/include/rte_ethdev_pci.h:75:35:·
> > >> error: invalid conversion from ‘void*’ to ‘rte_pci_device*’
> > >> [-fpermissive]
> > >>    struct rte_pci_device *pci_dev = bus_device;
> > >>                                     ^~~~~~~~~~
> > >> make[1]: *** [drivers/pmd.o] Error 1
> > >>
> > >> $ g++ --version
> > >> g++ (Ubuntu 7.3.0-27ubuntu1~18.04) 7.3.0  
> > > This problem is while building a driver with c++ compiler, but since the
> > > solution is a simple casting, which doesn't have any side affect, I am for
> > > getting the patch, any objection?  
> > 
> > It should be a decision that we support PMDs in C++ (if I understand
> > the usage correctly) and it will require all headers to be compatible and
> > ideally it should be checked by build automation (otherwise we will break
> > and fix it pretty often).  
> 
> Or as alternative, we probably can claim that PMDs in C++ are not supported,
> and if people like to do that - they have to deal with it on their own
> (create a C wrapper file, or so).
> Konstantin
> 


+1 no drivers or other parts of EAL in C++