[Xastir-dev] Travis-CI: gcc 8?

Tue Apr 23 20:42:07 PDT 2019

On Tue, Apr 23, 2019 at 08:35:12PM -0700, we recorded a bogon-computron collision of the <curt.we7u at gmail.com> flavor, containing:
> Your thinking on distributions to drop is sound. It's what I would want as
> well.
> 
> For the gcc-8 build should we add those two flags as well?

Perhaps, unless you really want to change how we force
string truncations.  Most of the cases where we're doing strncpy or snprintf
for this purpose makes it look like overkill to be using the string functions,
and in one case I looked at it was like we were using strncpy in a place where
a simple "memcpy" would have been more appropriate.  But there were so many
of these warnings that I decided just to shut them up with compiler options.
"Fixing" them seemed the lowest priority, since it was warning us that C might 
do exactly what we asked it to do, fully expecting it to do so.

Then again, the whole point of this exercise was to quiet down the build by
making sure we were not making any egregious mistakes, and we have indeed found
some real (if not catastrophic) errors during this process.  So I guess my 
answer is "I dunno."

> On Tue, Apr 23, 2019 at 8:29 PM Tom Russo <russo at bogodyn.org> wrote:
> 
> > On Tue, Apr 23, 2019 at 09:56:56PM -0500, we recorded a bogon-computron
> > collision of the <godfreja at gmail.com> flavor, containing:
> > > I can integrate it. Which build were you thinking of swapping out, or
> > would
> > > this be an addition?
> >
> > We should probably just drop the Ubuntu 14.04 build altogether.  Ubuntu
> > 14.04
> > is past its end of life (as of March 31st), so we shouldn't have to waste
> > resources supporting it.
> >
> > Having a 16.04 lite with ImageMagick, 16.04 full with GraphicsMagick
> > (with stock compiler) and 16.04 full with gcc8 is probably adequate for
> > Linux testing.  That gets us tested with at least one Linux distro that
> > isn't
> > past EOL, and one compiler that is at least close to the cutting edge that
> > will
> > appear in Linux distros that aren't stodgy.
> >
> > If Travis ever starts supporting Ubuntu 18.04, I'd advocate dropping all
> > but
> > one Ubuntu 16.04 build, then transitioning everything else to the newer
> > distro.
> >
> > I really do agree with Curt that it is worthwhile to add a gcc-8 build, if
> > either of you have the time to incorporate it.  I don't have that time.
> >
> > I am building with GCC 8 regularly now, and yes, there are "lots" of
> > warnings,
> > but most of them are warning us about using strncat, strncpy, snprintf,
> > and
> > other such restricted string operators *deliberately* to truncate strings
> > down to a length required by the APRS spec --- these strings *could* be
> > longer
> > than the spec, but we truncate down to what we're allowed in a packet.
> >
> > GCC 8 warns that these operations "could" truncate the string.  But that's
> > why we're using them.
> >
> > I have taken to disabling the two types of warnings that are the result of
> > our
> > deliberate use of these operators *specifically* to perform truncation, by
> > adding "-Wno-format-truncation -Wno-stringop-truncation" to my CFLAGS.
> >
> > It may be reasonable to use some other technique than these operators to
> > copy, say, a maximum of three characters out of a four character string
> > into a
> > three character array, but I felt that this warning was OK to ignore for
> > now,
> > since it's warning us that the operator might do exactly what we wanted it
> > to.
> >
> > > On Tue, Apr 23, 2019 at 9:24 PM Curt Mills <curt.we7u at gmail.com> wrote:
> > >
> > > > I have it building with gcc-8 on Xenial in my topic branch. Xenial is
> > > > Ubuntu-16.04. To get it to work I commented out the other builds and
> > just
> > > > build with the new one until I could make it work properly. Now I don't
> > > > know how to integrate what I've done with the earlier 4-build
> > .travis.yml
> > > > file we have on "master". Want to do the integration? If so I'll send
> > it
> > > > direct to you. BTW: It's showing LOTS of warnings! For the rest of you
> > out
> > > > there: That's actually what we want.
> > > >
> > > > On Tue, Apr 23, 2019 at 6:47 PM Jason Godfrey <godfreja at gmail.com>
> > wrote:
> > > >
> > > > > Maybe swap the Ubuntu 14.04 max build to use gcc 8 if that is a valid
> > > > > combination? The travis-ci documentation has the comment "If you are
> > on
> > > > an
> > > > > open-source plan, please remember that Travis CI provides this
> > service
> > > > free
> > > > > of charge to the community. So please only specify the matrix you
> > > > *actually
> > > > > need*."
> > > > >
> > > > > On Tue, Apr 23, 2019 at 7:39 PM Curt Mills <curt.we7u at gmail.com>
> > wrote:
> > > > >
> > > > > > We have Xastir building fairly cleanly on Travis-CI with three test
> > > > > cases:
> > > > > >
> > > > > > Ubuntu-14.04 max build
> > > > > > Ubuntu-14.04 min build
> > > > > > Ubuntu-16.04 max build
> > > > > >
> > > > > > Maybe what I should have said is that there aren't any Xastir code
> > > > > > errors/warnings being shown on those three, but a few warnings
> > appear
> > > > due
> > > > > > to problems inside the ImageMagick and Geotiff libraries.
> > > > > >
> > > > > > The OSX-10.13.3 build using the "clang" compiler is still showing
> > > > quite a
> > > > > > few warnings. Looks like really good stuff too as Clang is showing
> > some
> > > > > > warnings that GCC isn't, and some of them look like real problems
> > in
> > > > the
> > > > > > code.
> > > > > >
> > > > > > Now... Many of us are running newer OS'es than Ubuntu-16.04, but
> > the
> > > > list
> > > > > > of four above (including OSX) are all that are available on
> > Travis-CI
> > > > > > currently. Newer OS'es typically have a later release of GCC which
> > > > shows
> > > > > > more warnings (a good thing).
> > > > > >
> > > > > > There's another option for Travis-CI: Create another test case
> > with a
> > > > > gcc8
> > > > > > compiler:
> > > > > >
> > > > > > https://docs.travis-ci.com/user/languages/c/#gcc-on-linux
> > > > > >
> > > > > >
> > > > >
> > > >
> > https://docs.travis-ci.com/user/installing-dependencies/#adding-apt-sources-1
> > > > > >
> > > > > > Tom & Jason: interested?
> > > > > >
> > > > > > I'm running OpenSuSE-15.0 on my laptop here which has gcc-7.4.0
> > and it
> > > > > > shows more errors than the gcc-5.4.0 compiler on the Ubuntu-16.04
> > > > > Travis-CI
> > > > > > instance. Tom Russo is seeing more as well with his FreeBSD + Clang
> > > > > system.
> > > > > > --
> > > > > > Curt, WE7U        http://we7u.wetnet.net
> > > > > > http://www.sarguydigital.com
> > > > > > _______________________________________________
> > > > > > Xastir-dev mailing list
> > > > > > Xastir-dev at lists.xastir.org
> > > > > > http://xastir.org/mailman/listinfo/xastir-dev
> > > > > >
> > > > >
> > > > >
> > > > > --
> > > > > "The problem with quotes on the Internet is that it is often
> > difficult to
> > > > > verify their authenticity." - *Abraham Lincoln*
> > > > > _______________________________________________
> > > > > Xastir-dev mailing list
> > > > > Xastir-dev at lists.xastir.org
> > > > > http://xastir.org/mailman/listinfo/xastir-dev
> > > > >
> > > >
> > > >
> > > > --
> > > > Curt, WE7U        http://we7u.wetnet.net
> > > > http://www.sarguydigital.com
> > > > _______________________________________________
> > > > Xastir-dev mailing list
> > > > Xastir-dev at lists.xastir.org
> > > > http://xastir.org/mailman/listinfo/xastir-dev
> > > >
> > >
> > >
> > > --
> > > "The problem with quotes on the Internet is that it is often difficult to
> > > verify their authenticity." - *Abraham Lincoln*
> > > _______________________________________________
> > > Xastir-dev mailing list
> > > Xastir-dev at lists.xastir.org
> > > http://xastir.org/mailman/listinfo/xastir-dev
> >
> > --
> > Tom Russo    KM5VY
> > Tijeras, NM
> >
> >  echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z]
> > [n-z][a-m]
> >
> > _______________________________________________
> > Xastir-dev mailing list
> > Xastir-dev at lists.xastir.org
> > http://xastir.org/mailman/listinfo/xastir-dev
> >
> 
> 
> -- 
> Curt, WE7U        http://we7u.wetnet.net        http://www.sarguydigital.com

-- 
Tom Russo    KM5VY
Tijeras, NM  

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