cmakefmt

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Getting Started ​

cmakefmt is an opinionated formatter for CMake files (CMakeLists.txt and *.cmake). It takes CMake source, applies a consistent set of formatting rules, and outputs the result. Input must be valid UTF-8. If a file cannot be parsed, the formatter returns the input unchanged and exits with a non-zero status code -- it never silently corrupts unparseable input.

Installation ​

cargo install ​

bash
cargo install cmakefmt-cli

Prebuilt Binaries ​

Download prebuilt binaries for your platform from GitHub Releases:

  • linux-x64, linux-arm64
  • macos-x64, macos-arm64
  • windows-x64, windows-arm64

dprint Plugin ​

Add cmakefmt as a WASM plugin in your dprint.json:

json
{
  "plugins": [
    "https://github.com/azais-corentin/cmakefmt/releases/latest/download/cmakefmt-dprint.wasm"
  ]
}

Quick Start ​

Format a file and print the result to stdout:

bash
cmakefmt CMakeLists.txt

Format a file in place:

bash
cmakefmt --write CMakeLists.txt

Check formatting without modifying files (useful for CI -- exits with code 1 if changes are needed):

bash
cmakefmt --check CMakeLists.txt

Show a unified diff of what would change:

bash
cmakefmt --diff CMakeLists.txt

Format from stdin:

bash
cat CMakeLists.txt | cmakefmt --stdin

See the full list of flags in the CLI Reference.

Configuration ​

Create a .cmakefmt.toml (or cmakefmt.toml) in your project root. The formatter discovers config by walking from the formatted file's directory upward to the filesystem root. All keys use camelCase (snake_case is also accepted).

Example configuration:

toml
lineWidth = 120
indentWidth = 4
indentStyle = "space"
commandCase = "lower"
keywordCase = "upper"
closingParenNewline = true
lineEnding = "lf"
finalNewline = true
trimTrailingWhitespace = true
endCommandArgs = "remove"

sortArguments = ["SOURCES", "FILES"]
alignPropertyValues = true

ignorePatterns = ["build/**", "third_party/**"]
ignoreCommands = ["ExternalProject_Add"]

[perCommandConfig.if]
spaceBeforeParen = true

[perCommandConfig.elseif]
spaceBeforeParen = true

For a full list of options and their defaults, see the Configuration Reference (TOML) for CLI usage or Configuration Reference (JSON) for dprint plugin usage.

Editor Integration ​

External Formatter (stdin pipe) ​

Most editors can invoke an external command to format the current buffer. Configure your editor to pipe through:

bash
cmakefmt --stdin --assume-filename <path>

The --assume-filename flag tells cmakefmt which file path to use for config discovery (walking upward to find .cmakefmt.toml).

dprint ​

If you use dprint, add the cmakefmt WASM plugin to your dprint.json (see the Installation section above), then use dprint's editor extensions for VS Code, Neovim, or other supported editors.