[Bug c/105950] > O2 optimization causes runtime (SIGILL) during main initialization
jakub at gcc dot gnu.org
Tue Jun 14 09:36:09 GMT 2022
--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to John Kanapes from comment #11)
> (In reply to Richard Biener from comment #9)
> > Note that GCC 9 is no longer supported. Note one common error resulting in
> > SIGILL is when you fall through to an unreachable place which could be
> > padding
> > (like when there's a missing return in a function).
> gcc 9.40 is the distro gcc for Ubuntu 20.04, which is LTS and still
In this case it is Ubuntu that supports it, so you'd need to ask Ubuntu to fix
(if it is a compiler bug of course), because upstream GCC 9.5 was the last
release and there won't be any changes for the GCC 9 series. If it reproduces
with a newer compiler, it can be fixed upstream in the still supported releases
and perhaps Ubuntu could backport it if you ask them to.
> Does this mean that no action will be taken upon resolving this ticket?
Depends on if it is reproducible with a supported compiler.
> I am trying to recreate this bug in a smaller, more concise context.
> It is not an obvious bug. This is valid code, and it takes a large chain of
> previous steps to get it wrong at runtime. It used to work with previous
> gccs, but it now seems broken:(
Claiming it is valid code until it is analyzed is premature. It can very well
be undefined behavior in the code.
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