Re: [dpdk-dev] [PATCH v2] mk: fix build with shared pcap pmd

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2014-12-16 16:42, Neil Horman:
> On Tue, Dec 16, 2014 at 03:39:56PM +0100, Thomas Monjalon wrote:
> > 2014-12-16 08:58, Neil Horman:
> > > On Tue, Dec 16, 2014 at 12:04:44AM +0100, Thomas Monjalon wrote:
> > > > Some applications doesn't have the pcap link flag
> > > > when shared libraries are enabled.
> > > > Indeed in such case, pcap PMD must not be linked but pcap library should.
> > > > 
> > > > Actually -lpcap is always needed if pcap PMD is used,
> > > > and -lrte_pmd_pcap must be set only with static PMD library.
> > > > So the flags -lrte_pmd_pcap and -lpcap are enabled separately.
> > > > 
> > > > Workarounds in test-pmd/ and test-pipeline/ can be removed.
> > > > 
> > > > Reported-by: Stepan Sojka <stepan.sojka@adaptivemobile.com>
> > > > Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
> > [...]
> > > > --- a/mk/rte.app.mk
> > > > +++ b/mk/rte.app.mk
> > > > @@ -119,6 +119,10 @@ LDLIBS += -lm
> > > >  LDLIBS += -lrt
> > > >  endif
> > > >  
> > > > +ifeq ($(CONFIG_RTE_LIBRTE_PMD_PCAP),y)
> > > > +LDLIBS += -lpcap
> > > > +endif
> > > > +
> > > >  LDLIBS += --start-group
> > > >  
> > > >  ifeq ($(CONFIG_RTE_LIBRTE_KVARGS),y)
> > > > @@ -207,7 +211,7 @@ LDLIBS += -lrte_pmd_ring
> > > >  endif
> > > >  
> > > >  ifeq ($(CONFIG_RTE_LIBRTE_PMD_PCAP),y)
> > > > -LDLIBS += -lrte_pmd_pcap -lpcap
> > > > +LDLIBS += -lrte_pmd_pcap
> > > >  endif
> > > >  
> > > >  ifeq ($(CONFIG_RTE_LIBRTE_PMD_AF_PACKET),y)
> > > 
> > > Actually, what if we just add $(LDFLAGS) to the O_TO_S rule in mk/rte.lib.mk?
> > > Then in lib/librte_pmd_pcap/Makefile, we can just add LDFLAGS+=-lpcap, and the
> > > loading of the pcap pmd will itself require the loading of libpcap.  That would
> > > be a nice clean implementation that allows applications to just link the pmd and
> > > not have to worry about dependencies.  It would also allow us to clean up other
> > > dependencies like the xenvirt pmd and vhost.
> > 
> > Yes it makes sense. Could you test it please?
> > What about applying my patch (which keep the existing logic) as a first
> > fix/clean-up and then move -lpcap in PMD as a second step?
> > Proceeding this way would allow to integrate a safe fix for 1.8.0.
> > Maybe that linking pcap in the PMD could unveil new bugs with some distributions,
> > so it would need some time to validate it.
> > 
> ACK, I'm fine with your patch currently.  I'll revisit this after 1.8 is
> released
> Neil

Applied

-- 
Thomas