"ignoring packed attribute" warnings on Ubuntu 24.04

[andrewbird]

I thought I should mention this in case you are about to tag a release. Recently I get warnings when building fdpp on Ubuntu 24.04, but it does seem to work fine at run time. The warnings and the build script are attached.

t1.zip

[stsp]

gcc support is still very experimental,
as you can see eg from #271
The particular problem you are
seeing now, is this one:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83732

Another quite annoying problem
with diagnostic is this one:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84440
For which I have to use
-Wno-format -Wno-format-extra-args -Wno-error=format-security
which is exceptionally bad
(disables security checks).

And there are also:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120208
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93984
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109824
which are no longer relevant
for fdpp, but are still unfixed
in gcc.

So for now its not possible to
disable all gcc warnings even with
a brute-force approach of adding
-Wno-xxx for everything.
gcc evolves, but very, very slowly.
Not sure how many decades will
it take on both sides (fdpp and gcc)
to get to some convergence point.
Its quite a miracle that I've even
got it to work at all.

[stsp]

There is also a c++ standard
in a picture, that also evolves.
And for example I relied on
the "explicit lifetime management"
of c++23, but gcc refused to
implement it. So I had to make
a detour and write a different
architecture.

[andrewbird]

Wow it seems you have a lot of compiler issues to contend with. I did try a quick experiment to see if I could get Github problem matching to work https://github.com/ammaraskar/gcc-problem-matcher (I couldn't), but if the warnings are spurious anyway there's little value in pursuing it. Thanks for looking at it.

[stsp]

Interesting tool.
It may still be good, eg for
clang warnings.
You can use configure/make
for now to activate the clang
build. For meson its currently
not possible because we have
the compiler hard-coded here:
https://github.com/dosemu2/fdpp/blob/master/fdpp/kernel/toolchain.ini#L5
and meson is a piece of crap.
But I can at least add a
toolchain_clang.ini to allow
clang with meson...

[stsp]

You can now use clang with:
./configure.meson -c

[stsp]

Omg, it appears clang build is
not warning-less either...
Filled this ticket:
mesonbuild/meson#14689

[andrewbird]

Wow, meson has 2k issues and 550 open PRs!

[stsp]

Yep, and most of my reports
are closed w/o resolution, as
these guys are not interested
in cross-compilation scenarios.
So as you can see, tooling is
what makes things most
problematic. So far only
binutils and clang are absolutely
marvelous guys that keep
adding support for everything
we need.
Strictly speaking, clang doesn't
add anything for me, but they
spent a lot of time (also in gcc
bugzilla) helping me to move
from clang to gcc and stop
bothering them. :)