Add a cmake formatting tool in the CI

.gersemirc

@@ -0,0 +1,9 @@
+# Copyright (C) The DDC development team, see COPYRIGHT.md file
+#
+# SPDX-License-Identifier: MIT
+
+# yaml-language-server: $schema=https://raw.githubusercontent.com/BlankSpruce/gersemi/0.17.0/gersemi/configuration.schema.json
+
+definitions: ["cmake"]
+indent: 4
+line_length: 100

.github/workflows/tests.yml

@@ -26,6 +26,25 @@ jobs:
       if: always()
       uses: fsfe/reuse-action@v4
 
+  cmake-format:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install python3 virtual environments
+      run: |
+        sudo apt-get update
+        sudo apt-get --yes install python3-pip python3-venv
+    - name: Install gersemi
+      run: |
+        python3 -m venv ./gersemi
+        . ./gersemi/bin/activate
+        python3 -m pip install gersemi==0.17
+    - name: Run gersemi
+      run: |
+        . ./gersemi/bin/activate
+        gersemi --check cmake/DDCVendorConfiguration.cmake
+        find CMakeLists.txt tests/ examples/ benchmarks/ -name 'CMakeLists.txt' -exec gersemi --check '{}' '+'
+
   id_repo:
     runs-on: ubuntu-latest
     steps: