Hi,

I built a compile_commands.json over qemu code base, with help of bear.

When I use run-clang-tidy.py over it, I get several skipping warnings:

Error reading configuration from /home/elmarco/src/qemu/clang/../../hw/xen: directory doesn't exist.
Error reading configuration from /home/elmarco/src/qemu/clang/../../hw: directory doesn't exist.
Skipping /home/elmarco/src/qemu/clang/../../hw/xen/xen_pt_graphics.c. Compile command not found.

The files are not found because the base directory isn't correct.

[
    {
        "arguments": [
...
        ],
        "directory": "/home/elmarco/src/qemu/clang/x86_64-softmmu",
        "file": "../../hw/xen/xen_pt_graphics.c"
    },

(qemu has a recursive make build system for the various targets)