cmakefmt-rust 1.2.0

A lightning-fast, workflow-first CMake formatter — built in Rust, built to last.

The above demo was generated with VHS.

cmakefmt replaces the aging Python cmake-format tool with a single native binary. Same spirit. No Python.

• crates.io: cmakefmt-rust
• CLI name: cmakefmt

[!NOTE]

This project is independent from other Rust implementations, including: azais-corentin/cmakefmt and yamadapc/cmakefmt.

• Why cmakefmt?
• Performance
• Installation
• Quick Start
• Common Workflows
• Configuration
• Formatter Disable Regions
• Library Usage
• Documentation
• Project Layout
• Development
• Status
• License

Why cmakefmt?

• 104× faster — not a typo. Geometric-mean speedup of 104× over cmake-format on real-world per-file corpora, rising to 2,853× on whole-repository runs. Pre-commit hooks that once made you wince now finish before you blink.
• Zero dependencies. One binary. No Python environment, no virtualenv bootstrap, no dependency drift. Drop it in CI and forget about it.
• Built for actual workflows. --check, --diff, --staged, --changed, --files-from, --show-config, --explain-config, semantic verification, JSON reporting — all first-class, not scripted workarounds.
• Knows your commands. Teach cmakefmt the argument structure of your project's custom CMake functions and macros. No more generic token-wrapping for code you wrote.
• Errors that actually help. Parse and config failures come with file/line context, source snippets, and reproduction hints — not opaque parser noise.
• Designed for real repositories. Comment preservation, disable-region passthrough, config discovery, ignore files, Git-aware file selection, and opt-in parallelism are core features, not afterthoughts.

Performance

Geometric-mean per-file speedup: 104×. Whole-repository parallel runs (across 14 large open-source repos including LLVM, blender, opencv, gRPC, and oomph-lib) average 150× faster than cmake-format geo-mean (95× serial), with parallel mode delivering up to 2.9× over cmakefmt serial on large repositories.

Full methodology and profiler notes: cmakefmt.dev/performance/.

Update the pinned local corpus and generate local before/after review artifacts with:

python3 scripts/fetch-real-world-corpus.py
scripts/review-real-world-corpus.sh

Installation

Homebrew (macOS):

brew install cmakefmt/cmakefmt/cmakefmt

Cargo (any platform):

cargo install cmakefmt-rust

pip (any platform with Python):

pip install cmakefmt

conda-forge:

conda install -c conda-forge cmakefmt

Pre-built binaries (Linux, macOS, and Windows):

Download the .zip / .tar.gz for your platform from GitHub Releases, extract, and place the binary on your PATH.

Build from source:

git clone https://github.com/cmakefmt/cmakefmt
cd cmakefmt
cargo install --path .

Verify:

cmakefmt --version

Release channels and support levels are documented at cmakefmt.dev/release/. Shell completion installation instructions are available at cmakefmt.dev/install/.

Quick Start

cmakefmt config init               # generate a starter .cmakefmt.yaml
cmakefmt --check .                 # dry-run: just show which files would change
cmakefmt .                         # dry-run: preview formatted output; changed lines shown in blue
cmakefmt --diff .                  # dry-run: view a unified diff of what would change (like `git diff`)
cmakefmt --in-place .              # apply formatting across the whole project
cmakefmt --staged --check          # use in pre-commit hooks
cmakefmt --path-regex 'src/.*' .   # format CMake files only under src/

Common Workflows

Configuration

cmakefmt searches upward from each file for .cmakefmt.yaml, .cmakefmt.yml, or .cmakefmt.toml. YAML is recommended for larger configs.

Example .cmakefmt.yaml:

format:
  line_width: 100
  tab_size: 4

style:
  command_case: lower
  keyword_case: upper

markup:
  enable_markup: true

Debug which config a file is actually using:

cmakefmt --show-config-path src/CMakeLists.txt
cmakefmt --show-config src/CMakeLists.txt
cmakefmt --explain-config

Migrate from an existing cmake-format config:

cmakefmt --convert-legacy-config .cmake-format.py > .cmakefmt.yaml

Full config reference: cmakefmt.dev/config/.

Formatter Disable Regions

Selectively opt out of formatting with barrier comments.

There are three barrier styles:

1. Legacy cmake-format directives:

   # cmake-format: off
   set(MESSY_THING  a   b   c)   # kept verbatim
   # cmake-format: on
   

2. Native directive barriers, using either cmakefmt or the shorter fmt spelling:

   # cmakefmt: off
   set(MESSY_THING  a   b   c)   # kept verbatim
   # cmakefmt: on
   
   # fmt: off
   set(MESSY_THING  a   b   c)   # kept verbatim
   # fmt: on
   

3. Fence barriers, which toggle formatting on and off each time # ~~~ appears:

   # ~~~
   set(MESSY_THING  a   b   c)   # kept verbatim
   # ~~~
   

Use directive barriers when you want an explicit start/end marker, and fence barriers when you want a shorter toggle-style block.

Library Usage

cmakefmt is also available as a Rust library:

use cmakefmt::{format_source, Config};

fn main() -> Result<(), cmakefmt::Error> {
    let src = r#"target_link_libraries(foo PUBLIC bar baz)"#;
    let out = format_source(src, &Config::default())?;
    println!("{out}");
    Ok(())
}

Full API docs: cmakefmt.dev/api/.

Documentation

Start here: https://cmakefmt.dev.

Preview the full docs locally:

cd docs && npm install && npm run dev

Project Layout

cmakefmt/
├── docs/        # Astro + Starlight source published to cmakefmt.dev
├── src/         # CLI, library API, parser, config, spec, formatter
├── tests/       # integration tests, snapshots, and fixtures
├── benches/     # Criterion benchmarks
├── scripts/     # repo maintenance and docs helpers
└── .github/     # CI and Pages workflows

Key modules under src/:

• main.rs: CLI entry point and workflow orchestration
• lib.rs: public library API
• config/: config loading, merging, and legacy conversion
• parser/: hand-written parser, AST, and lowering pipeline
• spec/: built-in and user-defined command registry
• formatter/: AST-to-doc formatting logic and comment handling
• files.rs: file discovery and ignore handling

Development

cargo fmt --check                          # formatting
cargo clippy --all-targets -- -D warnings  # lints
cargo test                                 # all tests
cargo llvm-cov --workspace --all-targets   # coverage
cargo bench                                # benchmarks

Install pre-commit hooks:

pre-commit install
pre-commit install --hook-type pre-push

Status

The repository is stable and actively maintained. cmakefmt is still pre-1.0, so release packaging, package-manager distribution, and some output or API details may continue to evolve. The built-in command registry is audited through CMake 4.3.1.

Hit something unexpected? See Troubleshooting or run:

cmakefmt --debug --check path/to/CMakeLists.txt

License

cmakefmt is dual-licensed under MIT or Apache-2.0 at your option.