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.
>
> /Bruce
>
> [1] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
[1] https://gcc.gnu.org/gcc-9/changes.html
--
-
Regards,
Krzysztof(Chris) Kanas
