On Fri, 2018-08-10 at 14:44 -0400, Mark Johnston wrote: > On Fri, Aug 10, 2018 at 10:25:50AM +1000, Bruce Evans wrote: > > > > On Tue, 7 Aug 2018, Mark Johnston wrote: > > > > > > > > Log: > > > ifconfig: Fix use of _Noreturn. > > > > > > The _Noreturn is a function-specifier (like inline) which must preceed > > > the declarator. > > > > > > Submitted by: Sebastian Huber > > > MFC after: 1 week > > _Noreturn is even more broken than I knew. It should never be used. Here > > its use is wronger than usual. > > > > > > > > Modified: head/sbin/ifconfig/ifconfig.c > > > ============================================================================== > > > --- head/sbin/ifconfig/ifconfig.c Tue Aug 7 17:13:42 2018 > > > (r337425) > > > +++ head/sbin/ifconfig/ifconfig.c Tue Aug 7 17:25:38 2018 > > > (r337426) > > > @@ -109,7 +109,7 @@ static int ifconfig(int argc, char *const > > > *argv, int i > > > static void status(const struct afswtch *afp, const struct sockaddr_dl > > > *sdl, > > > struct ifaddrs *ifa); > > > static void tunnel_status(int s); > > > -static void usage(void) _Noreturn; > > > +static _Noreturn void usage(void); > > > > > > static struct afswtch *af_getbyname(const char *name); > > > static struct afswtch *af_getbyfamily(int af); > > FreeBSD code should use __dead2 since it is more portable (within > > FreeBSD) and doesn't have so mean syntactical restrictions. However, > > it only exists at all since it had similar syntactial restrictions > > when it was new (FreeBSD-1 used __dead, which must be placed like > > _Noreturn, but __dead2 uses __attribute__(()) which couldn't be placed > > there when it was new), and the macro that hides the details was renamed > > to inhibit misuse. Changing __dead2 to _Noreturn and moving it to satisfy > > the restricted syntax of the latter mainly broke support for old compilers > > where __dead2 cannot be placed there. > __dead2 was never present. _Noreturn was added in r317755, apparently > to appease Coverity. > > > > > However, all declarations of static usage() as non-returning are bogus, ... > I can only agree, especially since exit() is already declared with > _Noreturn in stdlib.h. I don't understand why __dead2/_Noreturn keeps > getting added to various usage() declarations. >
It was getting added to appease some not-very-capable static code analyzer. Not Coverity, not clang's builtin analyzer, something else someone was using, I forget the details. -- Ian _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
