Linting and Formatting ONNX Runtime Code

ONNX Runtime uses lintrunner for both C++ (clang-format) and Python (ruff).

Setup (one-time)

pip install -r requirements-lintrunner.txt
lintrunner init

Commands

lintrunner -a                                        # auto-fix changed files
lintrunner -a --all-files                            # auto-fix all files
lintrunner -a path/to/file.py path/to/other_file.cc  # auto-fix specific files
lintrunner f --all-files                             # format Python files only
lintrunner                                           # check without fixing (dry run)

Style rules

C++

• Google C++ Style with modifications (see docs/Coding_Conventions_and_Standards.md for full details)
• Max line length: 120 characters, but aim for 80 when possible
• Configured in .clang-format and .clang-tidy

Python

• Google Python Style Guide (extension of PEP 8)
• Max line length: 120 characters
• Configured in pyproject.toml

Agent tips

• Activate a Python virtual environment before installing dependencies. See "Python > Virtual environment" in AGENTS.md.
• If lintrunner is not yet set up, install and initialize first (see Setup).
• Prefer lintrunner -a (changed files only) over --all-files unless the user asks for a full sweep.