Isn't that the other way around? I thought clang was trying to support all gcc extensions to be able to build Linux kernel.
I would rather see both of these compilers to stay competitive to push themselves higher.
I would rather see both of these compilers to stay competitive to push themselves higher.
Those changes just don't get to upstream.
https://www.kernel.org/doc/html/latest/kbuild/llvm.html
I could be missing something, but I don't see any suggestion that you need a specific forked tree with patches to build with LLVM, and I've seen people filing bugs about using LLVM sanitizers to build the vanilla tree, so I don't think the expectation is that you need to apply a huge out of tree patchset for this to work any more?
AFAICT from the issues page, Clang and binutils/LLVM tools work fine with no patches for the mainstream archs and when not trying to be super-fancy with custom flags. The more non-mainstream one goes with arch or flags the more likely one will run into something.
[0] https://github.com/ClangBuiltLinux/linux/issues (Note they use github for issues/wiki, not code, so no surprise the 'linux version' in code is oldish).
My latest update was that not all patches were accepted upstream, or Google didn't care about upstreaming them, whatever.
There are some Linux Plumbers talks, or from Linaro, about this a years back.