

GCC 5 in Fedora - CUViper
http://developerblog.redhat.com/2015/02/10/gcc-5-in-fedora/

======
sqrt17
This gives me a strange impression of deja vu ... oh right, RedHat Linux and
the not-quite-standard gcc 2.96 version and the solution of having a separate
"kgcc" program that you could use to compile the programs that the default gcc
broke. I feel slightly old now.

The article does seem to imply that they want to ship the new gcc but keep
using the old ABI for a while to keep things compatible. Did I read that
right?

~~~
alexlarsson
Both ABIs are shipped in libstdc++, but all other libraries are build with the
old ABIs.

You can manually use the libstdc++ with the new ABI, but any of your
dependencies that use the problematic ABI must then be rebuild (and will be in
F23).

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mikekchar
Anyone know about LLVM and their plans? The reason I ask is that I'm starting
to do some Rust code and one of the nice features is that they use C++ name
mangling. I'm guessing I shouldn't assume that there will be interoperation
with installed C++ libraries in the short-mid term :-(.

~~~
the_why_of_y
LLVM does not need to worry about compatibility here because its libc++ is
relatively new and was designed with C++11 requirements in mind, whereas GNU
libstdc++ is >20 years old and could not possibly have anticipated these new
requirements.

OTOH on Linux you're most likely using clang together with libstdc++, and
whether that would use old or new ABI would depend on whether the magic macro
is defined in libstdc++ or by g++.

The article says _" the C++ standard library headers installed by the
libstdc++-devel RPM will have a different default value for the
_GLIBCXX_USE_CXX11_ABI macro"_ so that sounds like clang should do the same
thing as g++ here.

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cozzyd
Is any other distro moving to GCC5 so quickly? (Arch users?)

~~~
dmm
[https://packages.debian.org/experimental/gcc-5](https://packages.debian.org/experimental/gcc-5)

Debian has gcc-5 in experimental. A fact I'm taking advantage of because I
want to get Docker working on my sparc server but gccgo is broken on 4.9.

It was fixed a few months ago in the gcc repository but the bleeding edge gcc
repo has a broken libsanitizer on sparc. David Miller made some patches but
gcc won't accept them(has to go through upstream) and upstream(llvm) have been
ignoring them.

[https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59758](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59758)

So I'll have to disable asan or convince llvm to accept davm's patches and
then wait for gcc to merge from upstream.

~~~
AceJohnny2
I think the parent's comment was about using GCC5 to compile all the distro's
packages, not just providing GCC5 for its users. The Fedora article is unclear
about what they mean, but the consequences they refer to imply using GCC5 to
compile their packages.

As far as I know, while your link shows that Debian is getting ready to
provide it to its users, they haven't yet formed plans to use it to compile
their packages.

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shmerl
Is it stable enough already?

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nn3
So they want to ship a compiler if they can't even build their distribution
with it? Seriously?

Had to check the date, we are not yet in April.

~~~
noselasd
They're shipping gcc 5, but configures it to use a C++ ABI compatible with
older gcc versions, for reasons that does not have anything to do with "they
can't even build their distribution with it".

