Decoupling GCC From Debian By Using LLVM/Clang

[phoronix]

Phoronix: Decoupling GCC From Debian By Using LLVM/Clang

Back in March it was shared that LLVM's Clang compiler can build much of the Debian archive. This week at DebConf a status update was shared on using LLVM/Clang as an alternative compiler to GCC within Debian...

http://www.phoronix.com/vr.php?view=MTEzODQ

[droidhacker]

Which 12% won't build? Is it possible to build a system that boots and is functional with just Clang?

[ryao]

This is exactly what we are doing in Gentoo:

https://bugs.gentoo.org/show_bug.cgi?id=408963

Which 12% won't build? Is it possible to build a system that boots and is functional with just Clang?

Is it even possible to build Debian from source code as an end user?

GRUB makes heavy use of nested functions, which makes it impossible to build with Clang without doing a complete rewrite. Then there are other issues with glibc and a few other core packages. This is from my experience with Gentoo.

[uid313]

Can Clang/LLVM build an unpatched mainline Linux kernel yet?

[droidhacker]

This is exactly what we are doing in Gentoo:

https://bugs.gentoo.org/show_bug.cgi?id=408963



Is it even possible to build Debian from source code as an end user?

GRUB makes heavy use of nested functions, which makes it impossible to build with Clang without doing a complete rewrite. Then there are other issues with glibc and a few other core packages. This is from my experience with Gentoo.

Of COURSE its possible. If THEY can build it, ANYONE can build it.

[AJenbo]

Is it even possible to build Debian from source code as an end user?

You can use apt-build to do so.

[DeepDayze]

This is exactly what we are doing in Gentoo:

https://bugs.gentoo.org/show_bug.cgi?id=408963



Is it even possible to build Debian from source code as an end user?

GRUB makes heavy use of nested functions, which makes it impossible to build with Clang without doing a complete rewrite. Then there are other issues with glibc and a few other core packages. This is from my experience with Gentoo.

If Clang can't handle deeply nested functions that sounds like a bug to me and that the LLVM/Clang developers should address that issue as well as meshing with the existing glibc or providing the necessary patches to glibc that allow LLVM/Clang to build it yet not prevent other compilers from building it

[DeepDayze]

Can Clang/LLVM build an unpatched mainline Linux kernel yet?

AFAICT it can't. If Clang can build a kernel without requiring patches to the kernel sources that's the best thing

[AnonymousCoward]

If Clang can't handle deeply nested functions that sounds like a bug to me

No it's not, nested functions are a gcc extension.

[ryao]

If Clang can't handle deeply nested functions that sounds like a bug to me and that the LLVM/Clang developers should address that issue as well as meshing with the existing glibc or providing the necessary patches to glibc that allow LLVM/Clang to build it yet not prevent other compilers from building it

The fact that there is nesting is the issue, not the depth of it. The issue is that nested functions are illegal in both C and C++.