Re: [dpdk-dev] [PATCH v2] mk: report address of packed member as warning

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu, 2 May 2019 16:53:50 +0100
"Burakov, Anatoly" <anatoly.burakov@intel.com> wrote:

> On 02-May-19 3:13 PM, Reshma Pattan wrote:
> > gcc 9 on Fedora 30 gives an error
> > "taking address of packed member may result in an
> > unaligned pointer value" for -Waddress-of-packed-member.
> > 
> > Report it as warning instead of error to fix the build.
> > 
> > Snippet of build before fix
> > ...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];
> >        |            ^~~~~~~~~~~~~~~~~~~~~~~
> > 
> > Snippet of build after fix
> > ..lib/librte_eal/linux/eal/eal_memory.c: In function ‘remap_segment’:
> > ..lib/librte_eal/linux/eal/eal_memory.c:685:9: warning: taking address
> > of packed member of ‘struct rte_mem_config’ may result in an unaligned
> > pointer value [-Waddress-of-packed-member]
> >    685 |   msl = &mcfg->memsegs[msl_idx];
> >   
> 
> Fixing these would require an ABI break, because these are exposed 
> externally. Should we submit a deprecation notice for EAL?


Ideally mem config and related structures would not be exposed in the
API. Like lcore_config and eal_config it should be eal_private