build: Use nix to manage dev tooling starting with clang-tidy (Vowpal…

…Wabbit#4292)

* use nix for clang tidy and clang format

* test using nix for clang tidy

* check for only errors

* allow output from action

* dont lint tests with clang-tidy

* grouping and prevent false positives

* dont warn on magic numbers

* rename

* add missing change

* remove a few more lints

* back to 14

* Create .clang-format

* Update .clang-format

* use src dir to allow -fix

* add to format

* improve usability of script

.clang-tidy

@@ -1,5 +1,5 @@
 {
-  "Checks": "-*,readability-*,modernize-*,performance-*,cppcoreguidelines-pro-type-member-init,cppcoreguidelines-init-variables,readability-identifier-naming,-modernize-use-trailing-return-type,-readability-identifier-length,-readability-uppercase-literal-suffix",
+  "Checks": "-*,readability-*,modernize-*,performance-*,cppcoreguidelines-pro-type-member-init,cppcoreguidelines-init-variables,readability-identifier-naming,-modernize-use-trailing-return-type,-readability-magic-numbers,-readability-function-cognitive-complexity,-readability-identifier-length,-readability-uppercase-literal-suffix",
   "FormatStyle": "file",
   "WarningsAsErrors": "-*,performance-*,modernize-use-using,readability-braces-around-statements",
   "CheckOptions": [

.github/workflows/lint.yml

@@ -9,7 +9,7 @@ on:
     branches:
       - '*'
 
-concurrency: 
+concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.sha }}
   cancel-in-progress: true
 
@@ -138,18 +138,21 @@ jobs:
           fi
   run-clang-tidy:
     name: lint.c++.clang-tidy
-    container:
-      image: vowpalwabbit/ubuntu2004-dev:latest
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-        with:
-          submodules: recursive
-      - name: Install Ninja
-        shell: bash
+      - uses: actions/checkout@v3
+      - uses: cachix/install-nix-action@v18
+      - name: Run clang-tidy
         run: |
-          apt update
-          apt install -y libspdlog-dev libfmt-dev libboost-math-dev
-      - name: Run clang tidy
-        shell: bash
-        run: ./.scripts/linux/run-clang-tidy.sh
+          echo "::group::nix develop -c vw-clang-tidy"
+          nix develop -c vw-clang-tidy | tee tidy_out.txt || true
+          # Prevent false positives for THROW("error: ...") by using the prepended :
+          grep -A 3 ": error: " tidy_out.txt > tidy_onlyerrors.txt || true
+          echo "::endgroup::"
+          if [ -s tidy_onlyerrors.txt ]; then
+            # file has contents
+            echo "::group::clang-tidy errors"
+            cat tidy_onlyerrors.txt
+            echo "::endgroup::"
+            exit 11
+          fi

flake.nix

@@ -0,0 +1,110 @@
+{
+  # Currently, this flake only contains tools helpful for development.
+  # Over time, we may add a package definition and other things.
+  description = "Development utils for Vowpal Wabbit.";
+
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let pkgs = nixpkgs.legacyPackages.${system}; in
+      let
+        generate-compile-commands = ''
+          echo -n "Generating compile_commands.json... "
+          rm -rf $TMPDIR/compile_commands_build
+          mkdir -p $TMPDIR/compile_commands_build
+          cmake -S . -B "$TMPDIR/compile_commands_build" \
+            -DCMAKE_EXPORT_COMPILE_COMMANDS=On \
+            -DRAPIDJSON_SYS_DEP=On \
+            -DFMT_SYS_DEP=On \
+            -DSPDLOG_SYS_DEP=On \
+            -DVW_BOOST_MATH_SYS_DEP=On \
+            -DVW_ZLIB_SYS_DEP=On \
+            -DVW_GTEST_SYS_DEP=On \
+            -DVW_EIGEN_SYS_DEP=On \
+            -DBUILD_TESTING=Off \
+            -DVW_BUILD_VW_C_WRAPPER=Off > cmake_compile_commands_output.txt 2>&1
+          if [ $? -ne 0 ]; then
+            echo "Failed"
+            echo
+            cat cmake_compile_commands_output.txt >&2
+            exit 1
+          else
+            echo "Done"
+            rm cmake_compile_commands_output.txt
+          fi
+        '';
+      in
+      let
+        core-dependencies = [
+          pkgs.spdlog
+          pkgs.fmt
+          pkgs.zlib
+          pkgs.rapidjson
+          pkgs.eigen
+          pkgs.gtest
+          pkgs.boost
+          pkgs.cmake
+        ];
+      in
+      let
+        python-clang-tidy-package = pkgs.stdenv.mkDerivation {
+          name = "python-clang-tidy";
+          src = pkgs.fetchurl {
+            url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.6/clang-tools-extra-14.0.6.src.tar.xz";
+            sha256 = "sha256-fPO4/1bGXE0erjxWiD/EpsvD/586FTCnTWbkXScnGGY=";
+          };
+          sourceRoot = "clang-tools-extra-14.0.6.src";
+          phases = [ "unpackPhase" "installPhase" "fixupPhase" ];
+          propagatedBuildInputs = [ pkgs.python3 pkgs.clang-tools_14 ];
+          installPhase = ''
+            mkdir -p $out/bin
+            cp clang-tidy/tool/run-clang-tidy.py $out/bin
+            cp clang-tidy/tool/run-clang-tidy.py $out/bin/run-clang-tidy
+            cp clang-tidy/tool/clang-tidy-diff.py $out/bin
+            cp clang-tidy/tool/clang-tidy-diff.py $out/bin/clang-tidy-diff
+          '';
+        };
+      in
+      let
+        python-clang-format-package = pkgs.stdenv.mkDerivation {
+          name = "python-clang-format";
+          src = pkgs.fetchurl {
+            url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.6/clang-14.0.6.src.tar.xz";
+            sha256 = "sha256-K1hHtqYxGLnv5chVSDY8gf/glrZsOzZ16VPiY0KuQDE=";
+          };
+          sourceRoot = "clang-14.0.6.src";
+          phases = [ "unpackPhase" "installPhase" "fixupPhase" ];
+          propagatedBuildInputs = [ pkgs.python3 pkgs.clang-tools_14 ];
+          installPhase = ''
+            mkdir -p $out/bin
+            cp tools/clang-format/clang-format-diff.py $out/bin
+            cp tools/clang-format/clang-format-diff.py $out/bin/clang-format-diff
+          '';
+        };
+      in
+      let
+        clang-tidy-all-script = pkgs.writeShellScriptBin "vw-clang-tidy" ''
+          ${generate-compile-commands}
+          ${python-clang-tidy-package}/bin/run-clang-tidy -p $TMPDIR/compile_commands_build -quiet -header-filter=vw/* "$@"
+        '';
+      in
+      let
+        clang-tidy-diff-script = pkgs.writeShellScriptBin "vw-clang-tidy-diff" ''
+          ${generate-compile-commands}
+          ${python-clang-tidy-package}/bin/clang-tidy-diff -p1 -path $TMPDIR/compile_commands_build -r '^.*\.(cc|h)\$' -quiet -use-color "$@" <&0
+        '';
+      in
+      {
+        formatter = pkgs.nixpkgs-fmt;
+        devShell = pkgs.mkShell {
+          packages = [
+            python-clang-tidy-package
+            python-clang-format-package
+            clang-tidy-all-script
+            clang-tidy-diff-script
+          ] ++ core-dependencies;
+        };
+      }
+    );
+}

utl/clang-format.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Set environment variable GH_WORKFLOW_LOGGING to output logging that Azure pipelines will interpret as a warning.
 # Set environment variable WARNING_AS_ERROR to make the script exit with a non-zero code if issues are found.
@@ -33,7 +33,7 @@ clang-format --version
 
 for FILE in $(find . -type f -not -path './ext_libs/*' -not -path './cs/cli/*' \( -name '*.cc' -o -name "*.h" \) ); do
     if [[ "$1" == "check" ]]; then
-        diff $FILE <(clang-format $FILE);
+        clang-format --dry-run --Werror $FILE
         if [ $? -ne 0 ]; then
             ISSUE_FOUND="true"
             if [[ -v GH_WORKFLOW_LOGGING ]]; then