[gentoo-dev] Re: GCC upgrades, FUD and gentoo documentation

[Ryan Hill]

On Tue, 11 Oct 2011 03:27:04 +0000 (UTC)
Duncan <1i5t5.duncan@×××.net> wrote:

> The problem generally occurs when I decided I've waited long enough for a
> long released upstream gcc (4.x.1 and often 4.x.2 are released already!)
> to get unmasked even to ~arch.  Of course, having been thru this cycle a
> few times now, I well understand the reasons why it takes so long for
> Gentoo to bump gcc even to ~arch, and accept that I'll often have to dig
> thru bugs (often with patches attached for months, with no visible
> action, if I were to complain about Gentoo it'd be about the maintainers
> of those packages letting those bugs sit, or of packages that should be
> put up for someone else to maintain if the maintainers can no longer
> handle it, not about the efforts of the toolchain folks) and drop patches
> in /etc/portage/patches/* and/or overlay a package if the ebuild itself
> needs patched, and that a few packages might not yet have patches
> available.  That's not the problem.

I try to overcome that obstacle with the gcc-porting overlay.  I try to stick
all the patches that haven't been applied to the main tree in there. (try
being the key word - I really dropped the ball this release cycle as I
was graduating and then got stuck working 80hr weeks for a few months.)

> The problem is often cmake related.  Since cmake is C++, once I rebuild
> it against the new gcc, it tends to refuse to run if I switch to the old
> gcc.  Which means I'm SOL for the cmake-based package in question if it
> can't yet be built against the new gcc, since the package itself won't
> build with new gcc, and cmake won't run to let the package build with the
> old gcc.

Yeah I've run into situations like this many times.  I fear it will only get
worse as GCC seems to gather more and more external dependencies every
release.  If some future mandatory dependency links to libstdc++ it would
seem to me that building that package with a newer GCC could make it very
difficult to switch back.  We already have this situation with the graphite
libs (ppl/cloog-ppl), but fortunately it only breaks the graphite options,
not the entire compiler.

Anyways, we're getting off topic here.

-- 
fonts, gcc-porting,                  it makes no sense how it makes no sense
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