[WIP] C++ linter and formatter (experimental)

.clang-format

@@ -1,11 +1,11 @@
+---
+Language: Cpp
 AccessModifierOffset: -4
-AllowShortFunctionsOnASingleLine: Empty
-AllowShortIfStatementsOnASingleLine: Never
-AllowShortLambdasOnASingleLine: Empty
+BinPackArguments: false
 BreakBeforeBraces: Allman
-ColumnLimit: 0
-FixNamespaceComments: false
+BreakStringLiterals: false
+ColumnLimit: 120
 IncludeBlocks: Regroup
 IndentWidth: 4
 InsertBraces: true
-NamespaceIndentation: All
+...

.clang-tidy

@@ -0,0 +1,23 @@
+Checks: >
+  bugprone-*,
+  clang-analyzer-*,
+  cppcoreguidelines-*,
+  modernize-*,
+  performance-*,
+  readability-*,
+  -bugprone-easily-swappable-parameters,
+  -cppcoreguidelines-avoid-magic-numbers,
+  -cppcoreguidelines-avoid-non-const-global-variables,
+  -cppcoreguidelines-init-variables,
+  -cppcoreguidelines-macro-to-enum,
+  -cppcoreguidelines-macro-usage,
+  -cppcoreguidelines-pro-bounds-constant-array-index,
+  -modernize-macro-to-enum,
+  -modernize-use-auto,
+  -modernize-use-trailing-return-type,
+  -readability-convert-member-functions-to-static,
+  -readability-identifier-length,
+  -readability-magic-numbers,
+  -readability-misplaced-array-index,
+  -readability-static-accessed-through-instance,
+  -readability-uppercase-literal-suffix

.github/workflows/clang.yml

@@ -0,0 +1,247 @@
+name: Clang
+
+on:
+  pull_request:
+    branches:
+      - main
+
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  platformio:
+    name: PlatformIO environments
+    runs-on: ubuntu-latest
+    outputs:
+      environments: ${{ steps.print.outputs.environments }}
+      version: ${{ steps.print.outputs.version }}
+
+    env:
+      python-version: 3.13
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+
+      - name: Set up Python
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        with:
+          python-version: ${{ env.python-version }}
+          cache: pip
+          cache-dependency-path: .github/platformio/requirements.txt
+
+      - name: Set up PlatformIO
+        run: pip install -r .github/platformio/requirements.txt
+
+      - name: PlatformIO environments
+        id: print
+        run: |
+          echo "environments=$(pio project config --json-output | jq -c '[.[] | .[0] | select(startswith("env:")) | sub("^env:"; "")]')" >> "$GITHUB_OUTPUT"
+          echo "version=$(pio --version | awk '{print $NF}')" >> "$GITHUB_OUTPUT"
+
+  format:
+    name: Format
+    runs-on: ubuntu-latest
+
+    env:
+      clang-version: 21
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+
+      - name: Clang format
+        uses: cpp-linter/cpp-linter-action@b6edc0625e3941baa1797f4b4326adeab6890c97 # v2.16.7
+        id: format
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          version: ${{ env.clang-version }}
+          files-changed-only: false
+          format-review: true
+          passive-reviews: true
+          step-summary: true
+          style: file
+          tidy-checks: -*
+
+      - name: Summary
+        run: |
+          echo "Clang report:"
+          if [ -n "${{ github.event.pull_request.number }}" ]; then
+            echo "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}?pr=${{ github.event.pull_request.number }}"
+          else
+            echo "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+          fi
+          exit $(( ${{ steps.format.outputs.clang-format-checks-failed }} != 0 ))
+
+  tidy:
+    name: Tidy
+    needs: platformio
+    runs-on: ubuntu-latest
+
+    env:
+      clang-threshold: 358
+      clang-version: 21
+      python-version: 3.13
+
+    strategy:
+      matrix:
+        device-id:
+          - IKEA_FREKVENS
+          - IKEA_OBEGRANSAD
+
+        environment: ${{ fromJson(needs.platformio.outputs.environments) }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+
+      - name: Set up Python
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        with:
+          python-version: ${{ env.python-version }}
+          cache: pip
+          cache-dependency-path: |
+            .github/platformio/requirements.txt
+            scripts/requirements.txt
+
+      - name: Set up PlatformIO
+        run: pip install -r .github/platformio/requirements.txt
+
+      - name: Set up Cache
+        continue-on-error: true
+        uses: actions/cache@9255dc7a253b0ccc959486e2bca901246202afeb # v5.0.1
+        with:
+          key: platformio-cache-${{ runner.os }}-${{ runner.arch }}-${{ needs.platformio.outputs.version }}-${{ hashFiles('platformio.ini') }}
+          path: |
+            .platformio/.cache/downloads
+            .platformio/.cache/http
+
+      - name: PlatformIO compilation database
+        run: |
+          cat <<'EOL' > .env
+          ${{ matrix.device-id }}='true'
+          EXTENSION_ALEXA='true'
+          EXTENSION_BUTTON='true'
+          EXTENSION_HEAP='true'
+          EXTENSION_HOMEASSISTANT='true'
+          EXTENSION_INFRARED='true'
+          EXTENSION_MESSAGE='true'
+          EXTENSION_MICROPHONE='true'
+          EXTENSION_MQTT='true'
+          EXTENSION_OTA='true'
+          EXTENSION_PHOTOCELL='true'
+          EXTENSION_PLAYLIST='true'
+          EXTENSION_RESTFUL='true'
+          EXTENSION_RTC='true'
+          EXTENSION_SERVERSENTEVENTS='true'
+          EXTENSION_SIGNAL='true'
+          EXTENSION_WEBAPP='true'
+          EXTENSION_WEBSOCKET='true'
+          FONT_BRAILLE='true'
+          HOSTNAME='frekvens'
+          MODE_ANIMATION='true'
+          MODE_ARROW='true'
+          MODE_BINARYCLOCK='true'
+          MODE_BINARYEPOCH='true'
+          MODE_BLINDS='true'
+          MODE_BLINK='true'
+          MODE_BREAKOUTCLOCK='true'
+          MODE_BRIGHT='true'
+          MODE_CIRCLE='true'
+          MODE_COUNTDOWN='true'
+          MODE_DRAW='true'
+          MODE_EQUALIZER='true'
+          MODE_FIREWORK='true'
+          MODE_FLIES='true'
+          MODE_GAMEOFLIFE='true'
+          MODE_GLITTER='true'
+          MODE_GOOGLEWEATHER='true'
+          MODE_HOMEASSISTANTWEATHER='true'
+          MODE_HOMETHERMOMETER='true'
+          MODE_JAGGEDWAVEFORM='true'
+          MODE_LARGECLOCK='true'
+          MODE_LEAFFALL='true'
+          MODE_LINES='true'
+          MODE_METABALLS='true'
+          MODE_NOISE='true'
+          MODE_OPENMETEO='true'
+          MODE_OPENWEATHER='true'
+          MODE_PINGPONG='true'
+          MODE_PIXELSEQUENCE='true'
+          MODE_RAIN='true'
+          MODE_RING='true'
+          MODE_SCAN='true'
+          MODE_SMALLCLOCK='true'
+          MODE_SMOOTHWAVEFORM='true'
+          MODE_SNAKE='true'
+          MODE_STARS='true'
+          MODE_STREAM='true'
+          MODE_TICKER='true'
+          MODE_WAVEFORM='true'
+          MODE_WORLDWEATHERONLINE='true'
+          MODE_WTTRIN='true'
+          MODE_YR='true'
+          NAME='Frekvens'
+          EOL
+
+          cat <<'EOL' > firmware/include/config/secrets.h
+          #pragma once
+          #define GOOGLEWEATHER_KEY "redacted"
+          #define HOMEASSISTANT_HOST "homeassistant.local"
+          #define HOMEASSISTANT_KEY "redacted"
+          #define LATITUDE "0.000"
+          #define LOCATION "redacted"
+          #define LONGITUDE "0.000"
+          #define MQTT_HOST "mqtt.local"
+          #define MQTT_USER "redacted"
+          #define MQTT_KEY "redacted"
+          #define OPENMETEO_KEY "redacted"
+          #define OPENWEATHER_KEY "redacted"
+          #define PIN_CS 1
+          #define PIN_INT 2
+          #define PIN_IR 3
+          #define PIN_LDR 4
+          #define PIN_MIC 5
+          #define PIN_MOSI 6
+          #define PIN_OE 7
+          #define PIN_SCL 8
+          #define PIN_SCLK 9
+          #define PIN_SDA 10
+          #define PIN_SW1 11
+          #define PIN_SW2 12
+          #define RTC_DS3232
+          #define WIFI_KEY "redacted"
+          #define WIFI_SSID "redacted"
+          #define WORLDWEATHERONLINE_KEY "redacted"
+          EOL
+
+          pio run -t compiledb -e ${{ matrix.environment }}
+
+      - name: Clang tidy
+        uses: cpp-linter/cpp-linter-action@b6edc0625e3941baa1797f4b4326adeab6890c97 # v2.16.7
+        id: tidy
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          version: ${{ env.clang-version }}
+          files-changed-only: false
+          passive-reviews: true
+          step-summary: true
+          style: ""
+          tidy-checks: ""
+          tidy-review: true
+
+      - name: Summary
+        run: |
+          echo "Status: ${{ steps.tidy.outputs.clang-tidy-checks-failed }} checks failed, threshold for success is ${{ env.clang-threshold }}."
+          echo "Clang report:"
+          if [ -n "${{ github.event.pull_request.number }}" ]; then
+            echo "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}?pr=${{ github.event.pull_request.number }}"
+          else
+            echo "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+          fi
+          exit $(( ${{ steps.tidy.outputs.clang-tidy-checks-failed }} > ${{ env.clang-threshold }} ))