pre-commit

Out-of-the-box pre-commit for CMake projects (or one-shot ./python/mb-pre-commit-setup.py). The default CUSTOM hook runs on staged files, re-stages after auto-fixes, and avoids failed commits for fixable issues—except markdown and other non-auto-fixable hooks. The shipped example config includes Python hooks (ruff + pyupgrade).

Submodules: Git runs hooks from the submodule’s own .git, not the parent’s. Call mb_pre_commit_setup_subdirectory() from each submodule’s CMakeLists.txt (parent still needs mb_pre_commit via FetchContent). Each tree gets its own .venv and hook. PRE_COMMIT_TOOL_SWEEP_TARGET is different: it sweeps this mb-pre-commit package checkout in _deps, not an arbitrary consumer submodule.

Quick start

include(FetchContent)

FetchContent_Declare(
    mb_pre_commit
    GIT_REPOSITORY https://github.com/devmarkusb/pre-commit.git
    GIT_TAG v1.4.0
)

FetchContent_MakeAvailable(mb_pre_commit)

mb_pre_commit_setup_project()

mb_pre_commit_setup_project() picks top-level vs subdirectory setup via CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR (prefer over PROJECT_IS_TOP_LEVEL, which stays ON in add_subdirectory() trees without their own project()). In submodules with their own config, use:

mb_pre_commit_setup_project(PRE_COMMIT_INSTALL_EXAMPLE_CONFIG OFF)

That yields sweep target mb-pre-commit-sweep-<dir> (basename of the calling CMakeLists.txt folder, e.g. mb-pre-commit-sweep-devenv). Call mb_pre_commit_setup() or mb_pre_commit_setup_subdirectory() explicitly if you prefer.

Without CMake: ./python/mb-pre-commit-setup.py

After setup, the venv includes a launcher for the newest clang-format cached by pre-commit:

./.venv/bin/mb-pre-commit-clang-format --version   # Windows: .venv\Scripts\mb-pre-commit-clang-format.cmd

(./python/mb-pre-commit-clang-format.py remains for direct use.)

Integration

FetchContent_MakeAvailable runs this repo’s CMakeLists.txt, which pulls in cmake/mb-pre-commit.cmake—no ${mb-pre-commit_SOURCE_DIR} needed.

Vendoring: add cmake/ to CMAKE_MODULE_PATH and include(mb-pre-commit), or include(/path/to/pre-commit/cmake/mb-pre-commit.cmake).

On configure, a starter .pre-commit-config.yaml is copied to the project root (overwriting any existing file) from the best match under configs/vN/: largest vN with N ≤ your PRE_COMMIT_VERSION major (default 4.5.1 → configs/v4). Add v5, … for newer pre-commit majors. If none qualify, nothing is installed. Set PRE_COMMIT_INSTALL_EXAMPLE_CONFIG OFF to skip. Without a config, CUSTOM exits 0 (no-op); NATIVE uses whatever pre-commit install expects. Templates and configs resolve from this package’s directory regardless of where your CMakeLists.txt lives.

Sweep targets

When Git setup runs, you get mb-pre-commit-sweep (mb_pre_commit_sweep if the name is taken):

cmake --build . --target mb-pre-commit-sweep

Runs pre-commit run --all-files with the same venv and repo root as the hook. Disable with PRE_COMMIT_SWEEP_TARGET OFF; rename with PRE_COMMIT_SWEEP_TARGET <name>.

PRE_COMMIT_TOOL_SWEEP_TARGET <name> adds a second sweep at this package’s checkout (same venv/command, cwd = this tree). Omit or OFF for none. Skipped when PROJECT_SOURCE_DIR is already this checkout and the main sweep is enabled. If main sweep is OFF but tool sweep is set, you get one sweep for this tree only.

mb_pre_commit_setup(PRE_COMMIT_TOOL_SWEEP_TARGET mb-pre-commit-sweep-tool-repo)

Configure behavior

On CMake configure, mb_pre_commit_setup() (when Git hooks are available):

• Creates a project-local venv (default <project>/.venv).
• Pins pre-commit via pip (PRE_COMMIT_VERSION, default 4.5.1); upgrades only when mismatched.
• Installs a Git pre-commit hook into the effective hooks dir (git rev-parse --git-path hooks; works with worktrees).
• Registers sweep target(s) as above.

Non-Git trees (or unresolvable hooks dir): setup skipped, configure succeeds.

Requirements: find_package(Python3 REQUIRED COMPONENTS Interpreter); Git when a checkout exists. CUSTOM hook is Bash (pipefail, read -d '', xargs, mktemp)—needs Bash on PATH when Git runs hooks (Git Bash on Windows). Module needs CMake 3.21+; this repo’s CMakePresets.json targets CMake 4.0+.

Options

All defaults shown in the explicit call below:

mb_pre_commit_setup(
    PROJECT_SOURCE_DIR "${CMAKE_SOURCE_DIR}"
    PROJECT_BINARY_DIR "${CMAKE_BINARY_DIR}"
    PRE_COMMIT_MODE CUSTOM
    PRE_COMMIT_VERSION 4.5.1
    PRE_COMMIT_VENV_DIR "${CMAKE_SOURCE_DIR}/.venv"
    PRE_COMMIT_INSTALL_EXAMPLE_CONFIG ON
)

Argument	Default	Meaning
PROJECT_SOURCE_DIR	CMAKE_SOURCE_DIR	Git repo root for hooks.
PROJECT_BINARY_DIR	CMAKE_BINARY_DIR	Generated hook written here before install.
PRE_COMMIT_MODE	CUSTOM	CUSTOM or NATIVE (below).
PRE_COMMIT_VERSION	4.5.1	Exact pip version in venv.
PRE_COMMIT_VENV_DIR	${PROJECT_SOURCE_DIR}/.venv	Scripts/python.exe (Windows) or bin/python3.
PRE_COMMIT_INSTALL_EXAMPLE_CONFIG	ON	Refresh .pre-commit-config.yaml from configs/vN/.
PRE_COMMIT_SWEEP_TARGET	mb-pre-commit-sweep	add_custom_target for --all-files; OFF to skip. Falls back to mb_pre_commit_sweep if name taken.
PRE_COMMIT_TOOL_SWEEP_TARGET	*(unset)*	Second sweep at this package root when PROJECT_SOURCE_DIR is elsewhere. Omit/OFF: none.

mb_pre_commit_setup_subdirectory: same options; PROJECT_* default to CMAKE_CURRENT_*, PRE_COMMIT_INSTALL_EXAMPLE_CONFIG defaults OFF, sweep defaults to mb-pre-commit-sweep-<dir> (basename of CMAKE_CURRENT_LIST_DIR).

Relative PROJECT_SOURCE_DIR / PROJECT_BINARY_DIR / PRE_COMMIT_VENV_DIR resolve against CMAKE_SOURCE_DIR, CMAKE_BINARY_DIR, and PROJECT_SOURCE_DIR.

Cache MB_PRE_COMMIT_SETUP_LAYOUT: AUTO (default), TOP_LEVEL, or SUBDIRECTORY — force layout in tests/CI.

PRE_COMMIT_MODE

CUSTOM (default)

Configures cmake/pre-commit.in → ${PROJECT_BINARY_DIR}/pre-commit, copies to hooks dir when content differs (executable on non-Windows). The hook:

• Runs on staged paths only (added/copied/modified/renamed, existing files).
• Exits 0 if .pre-commit-config.yaml is missing.
• Runs python -m pre_commit run --hook-stage pre-commit --files … (venv python if available, else python3/python).
• On failure, re-stages surviving paths and retries (auto-fix without manual git add).

Re-configures when pre-commit.in changes (CMAKE_CONFIGURE_DEPENDS).

NATIVE

Runs python -m pre_commit install --install-hooks --hook-type pre-commit from PROJECT_SOURCE_DIR with the same venv—upstream hook and behavior.

Contributing and releases

Canonical hooks: configs/v4/.pre-commit-config.yaml. Root .pre-commit-config.yaml is a symlink for Dependabot/CI; consumers get a file copy from CMake. Edit configs/v4/ only.

Release tags via scripts/git-tag (clean tree required; --no-push for local only):

./scripts/git-tag --bump patch   # v3.0.0 -> v3.0.1
./scripts/git-tag --bump minor   # v3.0.0 -> v3.1.0
./scripts/git-tag v1.2.0

Not wired through CMake; copy/vendor/fetch or use a git alias downstream.