C++ Code Formatting Specification

Apache Doris uses clang-format to format C++ code, and provides wrapper scripts under the build-support directory so that developers can unify the format before submitting code.

Wrapper Scripts

Script	Purpose
build-support/clang-format.sh	Formats C/C++ code under be/src and be/test
build-support/check-format.sh	Checks the code format of be/src and be/test and prints the diff without modifying any files

Code Style Customization

• The Apache Doris code style is based on Google Style with minor customizations. The configuration file .clang-format is located at the Doris root directory.
• .clang-format is compatible with clang-format-16.0.0 and later.
• The .clang-format-ignore file lists code that should not be formatted, typically third-party libraries that should keep their original style.

Environment Setup

You need to install clang-format, or use a clang-format plugin provided by your IDE/editor. Doris currently uses clang-format 16 for code formatting (different versions of clang-format may produce different results).

Install clang-format

System	Recommended approach
Linux	Use the LDB toolchain (which already includes the matching version), or build/install the binary yourself
macOS	brew install clang-format@16

LDB toolchain notes: the latest version (>= v0.18) already includes a prebuilt clang-format 16.0.0 binary. For downloads, see ldb_toolchain_gen Releases.

Use an IDE Plugin

IDE	Plugin	Notes
CLion	ClangFormat (search and download under File -> Setting -> Plugins)	Make sure the clang-format version is 16
VS Code	Clang-Format extension	You need to manually specify the path to the clang-format executable

Usage

Run from the Command Line

1. Enter the Doris root directory:

   cd ${DORIS_HOME}

2. Run the formatting script:

   build-support/clang-format.sh

Note: the clang-format.sh script requires Python 3 to be installed on the machine.

Use clang-format in CLion

After installing the ClangFormat plugin, click Reformat Code to format the current file.

Use clang-format in VS Code

1. Install the Clang-Format extension.

2. Open the VS Code settings page, search for clang_format, and fill in the following configuration:

   {
       "clang_format_path": "$clang-format path$",
       "clang_format_style": "file"
   }

3. Right-click and select Format Document to format the file.

FAQ

Q: Will different clang-format versions cause inconsistent formatting?

Yes. Use the clang-format 16 series strictly, otherwise the format may not match what the project expects and CI may fail.

Q: Will third-party code also be formatted?

No. Directories listed in .clang-format-ignore are skipped, so that third-party dependencies keep their original code style.