On Thu, May 2, 2019 at 3:26 PM Bruce Richardson <bruce.richard...@intel.com> wrote:
> On Thu, May 02, 2019 at 12:07:17PM +0200, David Marchand wrote: > > 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> > > > --- > > > mk/toolchain/gcc/rte.vars.mk | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/ > rte.vars.mk > > > index d8b99faf6..b852fcfd7 100644 > > > --- a/mk/toolchain/gcc/rte.vars.mk > > > +++ b/mk/toolchain/gcc/rte.vars.mk > > > @@ -87,5 +87,8 @@ WERROR_FLAGS += -Wimplicit-fallthrough=2 > > > WERROR_FLAGS += -Wno-format-truncation > > > endif > > > > > > +# disable packed member unalign warnings > > > +WERROR_FLAGS += -Wno-address-of-packed-member > > > + > > > export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF > > > export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS > > > -- > > > 2.21.0 > > > > > > > > Not the best approach to me... > > > Agreed, but this fix does seem reasonable since we already disable this > warning > for clang. > > > Let me install a fedora 30 and have a look. > Hopefully you can come up with a better fix, but I think we need something > soon for 19.05, so this patch may be needed as a stop-gap fix. > Hiding this warning, we will never fix the places that could be fixed (and I found some where the packed attribute makes no sense to me). I'd prefer at least a -Wno-error=address-of-packed-member -- David Marchand
