community/developer-guide/cpp-format-code.md

---
title: C++ Code Formatting Specification
language: en
description: "Apache Doris C++ code formatting: clang-format tool configuration and usage from the command line and IDE."
keywords:
    - Apache Doris
    - C++ code formatting
    - clang-format
    - LDB toolchain
    - Clion
    - VS Code
    - BE development
---

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# C++ Code Formatting Specification

<!-- Knowledge type: Code specification -->
<!-- Applicable scenario: BE development / Pull Request submission -->

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](/community/source-install/compilation-with-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](https://github.com/amosbird/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:

    ```bash
    cd ${DORIS_HOME}
    ```

2. Run the formatting script:

    ```bash
    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:

    ```json
    {
        "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.