feat(ci): integrate clang-tidy for changed C/C++ files

.clang-tidy

@@ -0,0 +1,11 @@
+Checks: >
+  -*,
+  clang-analyzer-*,
+  bugprone-*,
+  performance-*,
+  modernize-use-nullptr,
+  modernize-use-override
+WarningsAsErrors: "*"
+HeaderFilterRegex: "^(src|tests|tools)/"
+FormatStyle: none
+SystemHeaders: false

.github/workflows/clang_tidy.yml

@@ -0,0 +1,146 @@
+name: Clang-Tidy
+
+on:
+  push:
+    branches: ["main"]
+    paths:
+      - "**/*.c"
+      - "**/*.cc"
+      - "**/*.cpp"
+      - "**/*.cxx"
+      - "**/*.h"
+      - "**/*.hpp"
+      - "CMakeLists.txt"
+      - "**/CMakeLists.txt"
+      - "cmake/**"
+      - ".clang-tidy"
+  pull_request:
+    branches: ["main"]
+    paths:
+      - "**/*.c"
+      - "**/*.cc"
+      - "**/*.cpp"
+      - "**/*.cxx"
+      - "**/*.h"
+      - "**/*.hpp"
+      - "CMakeLists.txt"
+      - "**/CMakeLists.txt"
+      - "cmake/**"
+      - ".clang-tidy"
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  clang_tidy:
+    name: Clang-Tidy Checks
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang-tidy cmake ninja-build
+
+      - name: Configure CMake and export compile commands
+        run: |
+          cmake -S . -B build -G Ninja \
+            -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
+            -DENABLE_HASWELL=ON \
+            -DBUILD_TOOLS=OFF
+
+      - name: Collect changed C/C++ files
+        id: changed_files
+        uses: tj-actions/changed-files@v46
+        with:
+          files: |
+            **/*.c
+            **/*.cc
+            **/*.cpp
+            **/*.cxx
+            !thirdparty/**
+            !build/**
+          separator: "\n"
+
+      - name: Filter changed files to compile database entries
+        id: tidy_files
+        if: steps.changed_files.outputs.any_changed == 'true'
+        run: |
+          python3 - <<'PY'
+          import json
+          import os
+          from pathlib import Path
+
+          changed = [line.strip() for line in """${{ steps.changed_files.outputs.all_changed_files }}""".splitlines() if line.strip()]
+          compile_db_path = Path("build/compile_commands.json")
+          with compile_db_path.open("r", encoding="utf-8") as f:
+              compile_db = json.load(f)
+
+          compile_entries = set()
+          for entry in compile_db:
+              file_path = entry.get("file")
+              if not file_path:
+                  continue
+              normalized = os.path.normpath(file_path).replace("\\", "/")
+              compile_entries.add(normalized)
+
+          selected = []
+          skipped = []
+          cwd = Path.cwd()
+          for file_path in changed:
+              if not Path(file_path).is_file():
+                  skipped.append(f"{file_path} (missing)")
+                  continue
+
+              abs_normalized = os.path.normpath(str((cwd / file_path).resolve())).replace("\\", "/")
+              rel_normalized = os.path.normpath(file_path).replace("\\", "/")
+
+              if abs_normalized in compile_entries or rel_normalized in compile_entries:
+                  selected.append(file_path)
+              else:
+                  skipped.append(f"{file_path} (no compile_commands entry)")
+
+          output_path = os.environ["GITHUB_OUTPUT"]
+          with open(output_path, "a", encoding="utf-8") as out:
+              out.write(f"any_tidy_files={'true' if selected else 'false'}\n")
+              out.write("all_tidy_files<<EOF\n")
+              out.write("\n".join(selected))
+              out.write("\nEOF\n")
+              out.write("skipped_files<<EOF\n")
+              out.write("\n".join(skipped))
+              out.write("\nEOF\n")
+          PY
+
+      - name: Show skipped files
+        if: steps.changed_files.outputs.any_changed == 'true' && steps.tidy_files.outputs.skipped_files != ''
+        run: |
+          echo "Skipping files:"
+          printf '%s\n' "${{ steps.tidy_files.outputs.skipped_files }}"
+
+      - name: Run clang-tidy
+        if: steps.tidy_files.outputs.any_tidy_files == 'true'
+        run: |
+          mapfile -t changed_files <<'EOF'
+          ${{ steps.tidy_files.outputs.all_tidy_files }}
+          EOF
+
+          for file in "${changed_files[@]}"; do
+            if [ -f "$file" ]; then
+              echo "Running clang-tidy on $file"
+              clang-tidy -p build --warnings-as-errors='*' "$file"
+            fi
+          done
+
+      - name: No clang-tidy files to analyze
+        if: steps.changed_files.outputs.any_changed != 'true' || steps.tidy_files.outputs.any_tidy_files != 'true'
+        run: |
+          echo "No changed source files with compile_commands entries matched clang-tidy patterns."

.gitignore

@@ -18,6 +18,7 @@ tests/de_integration/log
 tests/de_integration/*.log
 !.git*
 !.clang-format
+!.clang-tidy
 !.circleci
 !.drone.yml
 sdk/python/dist/