In February of this year the Clang C/C++ compiler for LLVM hit the milestone of self-hosting itself
after Clang's C support was declared production ready
(with the recently released LLVM 2.8, the C++ support is now deemed feature-complete
) just last October. In April another achievement was reached for LLVM/Clang and that was building much of FreeBSD's base operating system
. Today another milestone has been hit and that's building the Linux kernel for Debian to the point that it's functional and can run the X.Org Server both on bare metal and this can also be done within a QEMU virtualized environment.
Right now it's at least successfully building and hitting run-level five on an Apple MacBook running Debian GNU/Linux both on the hardware itself and virtualized. The kernel that this is being done with is Linux 2.6.36 using the x86_64 architecture with SMP. This build can also self-host itself with the developer reporting he's running a fourth-generation self-hosted Linux kernel built by LLVM/Clang and that the compiler build is also onto its fourth-generation build.
While kernel sub-systems like NUMA, SMP, the IPv4 networking stack, graphics drivers, and other drivers/firmware are being built, there still though are some things being left out of this Clang Linux kernel build. Some of the items not building right now are SELinux, POSIX ACLs, eCrypt, IPv6, anything using the crypto API, and Xen virtualization. The other huge caveat right now to this Linux kernel built by CLang is that kernel module loading is completely broken.
Bryce Lelbach, the developer announcing this work, is hoping to have the kernel in a much more Clang-friendly state in the coming months to the point that it could be considered production quality if using his Git repository that will contain these patches for Clang building.
The announcement of achieving this feat can be found in this email