Re: [dpdk-dev] [dpdk-stable] [PATCH 0/4] fix warnings with gcc 9 on Fedora 30

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, May 02, 2019 at 03:53:36PM +0200, David Marchand wrote:
>    On Thu, May 2, 2019 at 3:46 PM Bruce Richardson
>    <[1]bruce.richardson@intel.com> wrote:
> 
>      On Thu, May 02, 2019 at 03:32:20PM +0200, David Marchand wrote:
>      >    On Thu, May 2, 2019 at 3:24 PM Bruce Richardson
>      >    <[1][2]bruce.richardson@intel.com> wrote:
>      >
>      >      On Thu, May 02, 2019 at 02:32:41PM +0200, David Marchand
>      wrote:
>      >      >    On Thu, May 2, 2019 at 2:19 PM Thomas Monjalon
>      >      <[1][2][3]thomas@monjalon.net>
>      >      >    wrote:
>      >      >
>      >      >      01/05/2019 21:50, Bruce Richardson:
>      >      >      > This set of changes fixes warnings seen when
>      compiling DPDK
>      >      on
>      >      >      Fedora 30.
>      >      >      > In most cases these warnings appear to be false
>      positives,
>      >      which
>      >      >      means we
>      >      >      > have the option to just disable the warning. Because
>      the
>      >      changes
>      >      >      required
>      >      >      > to the code to silence the warnings are fairly small
>      I've
>      >      chosen
>      >      >      in all cases
>      >      >      > to change the code rather than disable the warnings,
>      but
>      >      I'm open
>      >      >      to doing
>      >      >      > the opposite if it's felt it's a better solution.
>      [One
>      >      thing I
>      >      >      didn't like
>      >      >      > about disabling the warnings is that the disabling
>      flags
>      >      are not
>      >      >      supported
>      >      >      > by clang, so adding them involves compiler checks
>      :-(]
>      >      >      >
>      >      >      > NOTE: this set does not cover all warnings with
>      GCC9, but
>      >      it does
>      >      >      cover
>      >      >      > those seen when building with meson. There is still
>      one
>      >      warning
>      >      >      disable
>      >      >      > flag needed when building with make, which will need
>      a
>      >      follow-on
>      >      >      set to
>      >      >      > fix.
>      >      >      >
>      >      >      > Bruce Richardson (4):
>      >      >      >   net/ixgbe: fix warning with GCC 9 on Fedora 30
>      >      >      >   bus/fslmc: fix printf of null pointer
>      >      >      >   raw/skeleton_rawdev: fix warnings with GCC 9 on
>      Fedora 30
>      >      >      >   raw/dpaa2_cmdif: fix warnings with GCC 9 on Fedora
>      30
>      >      >      Cc: [2][3][4]stable@dpdk.org
>      >      >      Applied, thanks
>      >      >
>      >      >    I had a comment on patch 2, and the bigger problem is
>      >      >    -Waddress-of-packed-member.
>      >      >    The quicker solution for now is to downgrade it to
>      warning only
>      >      so that
>      >      >    we can fix the parts later rather than globally disable
>      it.
>      >      >    --
>      >      Well, it is already a warning, it's just that with make we
>      build by
>      >      default
>      >      with -Werror when building from git.
>      >
>      >    Err, why don't we have -Werror for meson ?
>      >
>      Because it's generally not a good idea to use -Werror by default.
>      However,
>      the test-meson-build script (which we should all be using for test
>      compilation before upstreaming) sets it for all builds.
> 
>    Yes ok, so that old releases still build on newer toolchains.
>    As for the test-meson-builds.sh and test-build.sh scripts, they are
>    still widely unknown except by maintainers.
>    But at least, the ci build script would catch the errors, since it
>    configures with "meson build --werror -Dexamples=all $OPTS"
>    --

Yep, that's the idea. So long as it's easy enough for maintainers and CI to
use werror, we should be covered.