Patch By Patch, LLVM Clang Gets Better At Building The Linux Kernel

With each kernel revision, LLVM Clang gets closer to being able to build the mainline Linux kernel. There's now just a few dozen patches outstanding for LLVMLinux to be a mainline success.

Behan Webster gave his usual talk at LinuxCon in Chicago this week about the state of LLVMLinux -- building the Linux kernel with Clang rather than GCC. There's been many Phoronix articles about the topic so there isn't too much more to share beyond that many developers want to use Clang to compile the Linux kernel to lead to better code portability of the kernel, faster compilation times of Clang, potential performance differences, LLVM and Clang are more liberally licensed, and there's a host of other development extras with Clang.

At the LinuxCon Chicago presentation this week, Behan shared there's a total of 47 patches still outstanding that are trying to work their way upstream. These patches are needed to build the kernel cleanly without GCC. Thirteen of the 47 patches are architecture-agnostic, 8 are x86_64 specific, 16 are for AArch64, and 10 are for ARM. For helping new code going into the kernel, the LLVMLinux team has also begun tracking the linux-next branch to fend off potential breaks going into the next kernel cycle.

As has been the case for a while, on the compiler side all necessary patches are already upstream in LLVM/Clang.

Those wishing to find out more about the current state of LLVMLinux for building the kernel with Clang can find all the presentation slides in PDF form.