pytest-cppcheck

A pytest plugin that runs cppcheck static analysis on C/C++ source files. Each file is collected as a test item and reported as a pass or failure in the normal pytest output.

Useful for Python projects with C extension modules where you already run pytest and want cppcheck findings surfaced in the same test run.

Installation

pip install pytest-cppcheck

This pulls in cppcheck automatically via the cppcheck PyPI package. If you prefer a specific version, install cppcheck yourself via your system package manager (apt install cppcheck, brew install cppcheck, etc.) — the plugin uses whichever cppcheck is on PATH.

Usage

The plugin does nothing unless explicitly enabled:

pytest --cppcheck

This collects all .c and .cpp files and runs cppcheck on each one. Files with findings fail; clean files pass.

PASSED src/clean.c::CPPCHECK
FAILED src/buggy.c::CPPCHECK
  src/buggy.c:42:8: error: Array 'arr[10]' accessed at index 10, which is
  out of bounds. [arrayIndexOutOfBounds]

You can combine --cppcheck with your normal test run — Python tests and cppcheck items appear together in the results.

Configuration

All options go in pyproject.toml, pytest.ini, or setup.cfg under [pytest].

cppcheck_args

Extra arguments forwarded to every cppcheck invocation. This is the main configuration surface — use it for --enable, --suppress, and any other cppcheck flags. The plugin always passes --quiet and --error-exitcode=1 automatically.

With no cppcheck_args, cppcheck runs its default checks (mostly error-severity). Use --enable to broaden coverage. A good starting configuration:

[pytest]
cppcheck_args =
    --enable=warning,style,performance,portability
    --check-level=exhaustive

cppcheck_extensions

File extensions to collect. Default: .c .cpp.

[pytest]
cppcheck_extensions = .c .cpp .h

Markers

All cppcheck items are marked with cppcheck, so you can select or exclude them with -m:

pytest --cppcheck -m cppcheck           # only cppcheck
pytest --cppcheck -m "unit or cppcheck" # unit tests + cppcheck
pytest --cppcheck -m "not cppcheck"     # everything except cppcheck

Caching

Results are cached based on file modification time and cppcheck_args. On subsequent runs, files that previously passed are skipped. The cache is automatically invalidated when a file is modified or cppcheck_args changes. Caching relies on pytest's built-in cache provider (the .pytest_cache directory). If the cache provider is disabled (for example with -p no:cacheprovider), results will not be cached and all files will be re-checked on each run.

To force a full re-check:

pytest --cppcheck --cache-clear

License

MIT