> -----Original Message----- > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Bruce Richardson > Sent: Friday, May 3, 2019 5:25 PM > To: Jerin Jacob Kollanukkaran <jer...@marvell.com> > Subject: Re: [dpdk-dev] [PATCH] mk: disable warning with gcc 9 on Fedora > 30 > > On Fri, May 03, 2019 at 04:01:38PM +0000, Jerin Jacob Kollanukkaran wrote: > > > -----Original Message----- > > > From: dev <dev-boun...@dpdk.org> On Behalf Of Thomas Monjalon > > > Sent: Thursday, May 2, 2019 9:27 PM > > > To: Reshma Pattan <reshma.pat...@intel.com> > > > Cc: dev@dpdk.org; David Marchand <david.march...@redhat.com> > > > Subject: Re: [dpdk-dev] [PATCH] mk: disable warning with gcc 9 on > > > Fedora 30 > > > > > > 02/05/2019 17:00, David Marchand: > > > > On Thu, May 2, 2019 at 11:33 AM Reshma Pattan > > > > <reshma.pat...@intel.com> > > > > wrote: > > > > > > > > > gcc 9 on Fedora 30 gives an error "taking address of packed > > > > > member may result in an unaligned pointer value" warnings. > > > > > > > > > > For clang builds this warning is already disabled, so disable > > > > > "-Waddress-of-packed-member" for gcc builds also. > > > > > > > > > > Snippet of build error: > > > > > ...lib/librte_eal/linux/eal/eal_memalloc.c: In function > ‘alloc_seg_walk’: > > > > > ...lib/librte_eal/linux/eal/eal_memalloc.c:768:12: error: taking > > > > > address of packed member of ‘struct rte_mem_config’ may result > > > > > in an unaligned pointer value [-Werror=address-of-packed-member] > > > > > 768 | cur_msl = &mcfg->memsegs[msl_idx]; > > > > > | ^~~~~~~~~~~~~~~~~~~~~~~ > > > > > > > > > > Signed-off-by: Reshma Pattan <reshma.pat...@intel.com> > > > > > > > > > > > > > > Tested on rhel-7 and fedora-30. > > > > Tested-by: David Marchand <david.march...@redhat.com> > > > > > > Applied, thanks > > > > Its been found that one of the armv7 toolchain treats > > -Wno-address-of-packed-member as unrecognized command line option, > > Hence armv7 build fails on dpdk.org master now. Not sure it is specific > to armv7 or compiler? > > > > Armv7 is not maintained and I don’t think, it has any use case for DPDK. > > If everyone agrees IMO it is better remove the arm 32bit support. > > > > arm-buildroot-linux-gnueabihf-gcc -v > > Using built-in specs. > > COLLECT_GCC=/opt/armv7-eabihf--glibc--stable-2018.11-1/ > > bin/arm-buildroot-linux-gnueabihf-gcc.br_real > > COLLECT_LTO_WRAPPER=/opt/armv7-eabihf--glibc--stable-2018.11-1/ > > libexec/gcc/arm-buildroot-linux-gnueabihf/7.3.0/lto-wrapper > > Target: arm-buildroot-linux-gnueabihf > > Configured with: ./configure > > --prefix=/opt/armv7-eabihf--glibc--stable-2018.11-1 > > --sysconfdir=/opt/armv7-eabihf--glibc--stable-2018.11-1/etc > > --enable-static --target=arm-buildroot-linux-gnueabihf > > --with-sysroot=/opt/armv7-eabihf--glibc--stable-2018.11-1/ > > arm-buildroot-linux-gnueabihf/sysroot > > --disable-__cxa_atexit --with-gnu-ld --disable-libssp --disable- > multilib > > --with-gmp=/opt/armv7-eabihf--glibc--stable-2018.11-1 > > --with-mpc=/opt/armv7-eabihf--glibc--stable-2018.11-1 > > --with-mpfr=/opt/armv7-eabihf--glibc--stable-2018.11-1 > > --with-pkgversion='Buildroot 2018.08.1-00003-g576b333' > > --with-bugurl=http://bugs.buildroot.net/ --disable-libquadmath > > --enable-tls --disable-libmudflap --enable-threads --without-isl > > --without-cloog --disable-decimal-float --with-abi=aa > > pcs-linux --with-cpu=cortex-a9 --with-fpu=vfpv3-d16 --with- > float=hard > > --with-mode=arm --enable-languages=c,c++ > > --with-build-time-tools=/opt/armv7-eabihf--glibc--stable-2018.11-1/ > > arm-buildroot-linux-gnueabihf/bin --enable-shared --disable-libgomp > > Thread model: posix > > gcc version 7.3.0 (Buildroot 2018.08.1-00003-g576b333) > > > > error log: > > > > dpdk.org/lib/librte_eal/linux/eal/eal_vfio_mp_sync.c: At top level: > > cc1: error: unrecognized command line option > > ‘-Wno-address-of-packed-member’ [-Werror] > > cc1: all warnings being treated as errors > > > > Are you sure there is not another error as well? GCC silently ignores > flags like this one normally, but does report them as unrecognised if-and- > only-if another error or warning is given too. > > /Bruce
For completeness, ref: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html "When an unrecognized warning option is requested (e.g., -Wunknown-warning), GCC emits a diagnostic stating that the option is not recognized. However, if the -Wno- form is used, the behavior is slightly different: no diagnostic is produced for -Wno-unknown-warning unless other diagnostics are being produced. This allows the use of new -Wno- options with old compilers, but if something goes wrong, the compiler warns that an unrecognized option is present."
