Using clangd

Naturally, the first step is to ensure that clangd is correctly integrated with your editor. It's always safe to run clangd on the command line to ensure that it starts up correctly.

This language server requires the existence of a compiler database to inform itself about include paths and such. The kernel source tree contains a script to generate one:

$ ./scripts/clang-tools/gen_compile_commands.py

This script uses the *.cmd files generated by Kbuild, so the kernel must have been built at least once before in order to succeed.

When the editor is launched, ensure that clangd is executed in the same directory as the compile_commands.json database. For compiling out of tree (e.g. on Gentoo), this usually means one has to symlink the compiler database into the source directory:

$ ln -s $PWD/compile_commands.json /usr/src/linux/compiler_commands.json