On Tue, Jul 23, 2019 at 09:05:50AM +0000, Krzysztof Kanas wrote: > On 19-07-22 14:44, Bruce Richardson wrote: > > External Email > > > > ---------------------------------------------------------------------- > > On Mon, Jul 22, 2019 at 02:39:59PM +0200, kka...@marvell.com wrote: > > > From: Krzysztof Kanas <kka...@marvell.com> > > > > > > gcc prior 9 don't will add additional warning for unrecognized command > > > line option, but only when there is some other warning in the code, e.g > > > unused variable. > > > > > I don't think this behaviour has changed in gcc 9. I just did a test > > compile with gcc 9.1, and no warning was printed for flag > > "-Wno-random-warnings". The online docs also make no mention of this > > behaviour being conditional on GCC version [1]. > GCC changelog show that from 9.0 -Waddress-of-packed-member was added > [1]. > > Test shows me that GCC prior to 9.0 won't complain about this flag, but > in case of other warnings in file GCC will complain, e.g., > > cat > a.c > int main(int argc, char **argv) > { > int a; > return 0; > } > > # gcc -Wall -Wno-address-of-packed-member a.c > > a.c: In function ‘main’: > a.c:3:6: warning: unused variable ‘a’ [-Wunused-variable] > int a; > ^ > a.c: At top level: > cc1: warning: unrecognized command line option ‘-Wno-address-of-packed-member’ > > But when line `int a;' is removed then no warning is issued. > > Also I detected this, due to difference with meson build. Meson checks > if compiler supports this flag and will not issue > -Wno-address-of-packed-member to compiler. > Yes, all that is correct, but there is no behaviour change in GCC 9. This does not require a fix IMHO.
/Bruce