title: Apache Mesos - ClangFormat layout: documentation


ClangFormat is an automatic source code formatting tool which helps us focus on the code rather than the formatting.

The provided configurations try to honor the Mesos C++ Style Guide as much as possible, but there are some limitations which require manual attention. Even with these limitations however, ClangFormat will be extremely useful for your workflow!


Install clang-format-3.8

Ubuntu 14.04

# Add llvm repository
sudo apt-add-repository "deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty main"

# Ensure apt-get is up to date.
sudo apt-get update

# Install clang-format-3.8
sudo apt-get install clang-format-3.8

OS X El Capitan

# Install clang-format (3.8).
$ brew install clang-format

Formatting Configuration

By default, ClangFormat uses the configuration defined in a .clang-format or _clang-format file located in the nearest parent directory of the input file. The bootstrap script creates a .clang-format symlink at the top-level directory which points to support/clang-format for ClangFormat to find.

Editor Integration


Add the following to your .vimrc:


map <C-K> :pyf /usr/share/vim/addons/syntax/clang-format-3.8.py<cr>
imap <C-K> <c-o>:pyf /usr/share/vim/addons/syntax/clang-format-3.8.py<cr>


map <C-K> :pyf /usr/local/share/clang/clang-format.py<cr>
imap <C-K> <c-o>:pyf /usr/local/share/clang/clang-format.py<cr>

The first line enables clang-format for NORMAL and VISUAL mode, the second line adds support for INSERT mode. Change C-K to another binding if you need clang-format on a different key (C-K stands for Ctrl+k).

With this integration you can press the bound key and clang-format will format the current line in NORMAL and INSERT mode or the selected region in VISUAL mode. The line or region is extended to the next bigger syntactic entity.

It operates on the current, potentially unsaved buffer and does not create or save any files. To revert a formatting, just undo.

Source: http://llvm.org/releases/3.8.0/tools/clang/docs/ClangFormat.html


Add the following to your .emacs:


(load "/usr/share/emacs/site-lisp/clang-format-3.8/clang-format.el")
(global-set-key [C-M-tab] 'clang-format-region)


(load "/usr/local/share/clang/clang-format.el")
(global-set-key [C-M-tab] 'clang-format-region)

This binds the function clang-format-region to C-M-tab, which then formats the current line or selected region.

Source: http://llvm.org/releases/3.8.0/tools/clang/docs/ClangFormat.html

Known Limitations

  • Parameters and arguments should be indented by 4 spaces rather than 2.
  • Should not follow Google's style of wrapping on open parentheses, we should try to reduce “jaggedness” in the code.