build: integrate clang-tidy into CI

This still has utterly unacceptably bad output format design that I
would not inflict on anyone I like, but it *does* now exist, and you
*can* find the errors in the log.

Future work would obviously be to fix that and integrate the actual
errors into Gerrit using codechecker or so.

Followup issue: https://git.lix.systems/lix-project/lix/issues/457

Fixes: https://git.lix.systems/lix-project/lix/issues/147
Change-Id: Ifca22e443d357762125f4ad6bc4f568af3a26c62

1 files changed, 15 insertions, 0 deletions

diff --git a/flake.nix b/flake.nix
index c160daed9..662469479 100644
--- a/flake.nix
+++ b/flake.nix
@@ -282,6 +282,10 @@
           # cheaper x86_64-linux compute in CI.
           # It is clangStdenv because clang's sanitizers are nicer.
           asanBuild = self.packages.x86_64-linux.nix-clangStdenv.override {
+            # Improve caching of non-code changes by not changing the
+            # derivation name every single time, since this will never be seen
+            # by users anyway.
+            versionSuffix = "";
             sanitize = [
               "address"
               "undefined"
@@ -310,6 +314,17 @@
               touch $out
             '';
 
+          # clang-tidy run against the Lix codebase using the Lix clang-tidy plugin
+          clang-tidy =
+            let
+              nixpkgs = nixpkgsFor.x86_64-linux.native;
+              inherit (nixpkgs) pkgs;
+            in
+            pkgs.callPackage ./package.nix {
+              versionSuffix = "";
+              lintInsteadOfBuild = true;
+            };
+
           # Make sure that nix-env still produces the exact same result
           # on a particular version of Nixpkgs.
           evalNixpkgs =