To expand on that, usually one defines a non-static variable, in a .c file, only when an "extern" declaration of the same variable is already visible from #including an .h file. A definition without a previous declaration usually means that the .h file was forgotten.
On Tue, Aug 20, 2013 at 02:48:57PM -0700, Alex Wang wrote: > I found the answer from this thread: > http://openvswitch.org/pipermail/dev/2011-May/008608.html > > > > On Tue, Aug 20, 2013 at 2:02 PM, Alex Wang <al...@nicira.com> wrote: > > > May I ask, what rule is this? > > > > Should we always declare global variable before defining it? or just when > > it is enclosed by macros? > > > > Also, when the "!USE_LINKER_SECTIONS", we should modify the coverage.c the > > same way. I'll send out a patch, > > > > > > On Tue, Aug 20, 2013 at 1:44 PM, Ben Pfaff <b...@nicira.com> wrote: > > > >> On Mon, Aug 19, 2013 at 12:32:06PM -0700, Alex Wang wrote: > >> > Just noticed, when compiling with sparse, it issues the warnings like: > >> > > >> > """ > >> > lib/netdev-linux.c:76:1: warning: symbol 'counter_netdev_set_policing' > >> was > >> > not declared. Should it be static? > >> > lib/netdev-linux.c:77:1: warning: symbol 'counter_netdev_arp_lookup' was > >> > not declared. Should it be static? > >> > lib/netdev-linux.c:78:1: warning: symbol 'counter_netdev_get_ifindex' > >> was > >> > not declared. Should it be static? > >> > """ > >> > >> Ouch, thanks, I folded in this incremental to fix that: > >> > >> diff --git a/lib/coverage.h b/lib/coverage.h > >> index 73b027a..3d1a115 100644 > >> --- a/lib/coverage.h > >> +++ b/lib/coverage.h > >> @@ -54,6 +54,7 @@ struct coverage_counter { > >> { \ > >> *counter_##COUNTER##_get() += n; \ > >> } \ > >> + extern struct coverage_counter counter_##COUNTER; \ > >> struct coverage_counter counter_##COUNTER \ > >> = { #COUNTER, COUNTER##_count, 0 }; \ > >> extern struct coverage_counter *counter_ptr_##COUNTER; \ > >> > > > > _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
