| =========== |
| ClangFormat |
| =========== |
| |
| `ClangFormat` describes a set of tools that are built on top of |
| :doc:`LibFormat`. It can support your workflow in a variety of ways including a |
| standalone tool and editor integrations. |
| |
| |
| Standalone Tool |
| =============== |
| |
| :program:`clang-format` is located in `clang/tools/clang-format` and can be used |
| to format C/C++/Java/JavaScript/JSON/Objective-C/Protobuf/C# code. |
| |
| .. code-block:: console |
| |
| $ clang-format -help |
| OVERVIEW: A tool to format C/C++/Java/JavaScript/JSON/Objective-C/Protobuf/C# code. |
| |
| If no arguments are specified, it formats the code from standard input |
| and writes the result to the standard output. |
| If <file>s are given, it reformats the files. If -i is specified |
| together with <file>s, the files are edited in-place. Otherwise, the |
| result is written to the standard output. |
| |
| USAGE: clang-format [options] [<file> ...] |
| |
| OPTIONS: |
| |
| Clang-format options: |
| |
| --Werror - If set, changes formatting warnings to errors |
| --Wno-error=<value> - If set don't error out on the specified warning type. |
| =unknown - If set, unknown format options are only warned about. |
| This can be used to enable formatting, even if the |
| configuration contains unknown (newer) options. |
| Use with caution, as this might lead to dramatically |
| differing format depending on an option being |
| supported or not. |
| --assume-filename=<string> - Override filename used to determine the language. |
| When reading from stdin, clang-format assumes this |
| filename to determine the language. |
| --cursor=<uint> - The position of the cursor when invoking |
| clang-format from an editor integration |
| --dry-run - If set, do not actually make the formatting changes |
| --dump-config - Dump configuration options to stdout and exit. |
| Can be used with -style option. |
| --fallback-style=<string> - The name of the predefined style used as a |
| fallback in case clang-format is invoked with |
| -style=file, but can not find the .clang-format |
| file to use. |
| Use -fallback-style=none to skip formatting. |
| --ferror-limit=<uint> - Set the maximum number of clang-format errors to |
| emit before stopping (0 = no limit). Used only |
| with --dry-run or -n |
| -i - Inplace edit <file>s, if specified. |
| --length=<uint> - Format a range of this length (in bytes). |
| Multiple ranges can be formatted by specifying |
| several -offset and -length pairs. |
| When only a single -offset is specified without |
| -length, clang-format will format up to the end |
| of the file. |
| Can only be used with one input file. |
| --lines=<string> - <start line>:<end line> - format a range of |
| lines (both 1-based). |
| Multiple ranges can be formatted by specifying |
| several -lines arguments. |
| Can't be used with -offset and -length. |
| Can only be used with one input file. |
| -n - Alias for --dry-run |
| --offset=<uint> - Format a range starting at this byte offset. |
| Multiple ranges can be formatted by specifying |
| several -offset and -length pairs. |
| Can only be used with one input file. |
| --output-replacements-xml - Output replacements as XML. |
| --sort-includes - If set, overrides the include sorting behavior |
| determined by the SortIncludes style flag |
| --style=<string> - Coding style, currently supports: |
| LLVM, Google, Chromium, Mozilla, WebKit. |
| Use -style=file to load style configuration from |
| .clang-format file located in one of the parent |
| directories of the source file (or current |
| directory for stdin). |
| Use -style="{key: value, ...}" to set specific |
| parameters, e.g.: |
| -style="{BasedOnStyle: llvm, IndentWidth: 8}" |
| --verbose - If set, shows the list of processed files |
| |
| Generic Options: |
| |
| --help - Display available options (--help-hidden for more) |
| --help-list - Display list of available options (--help-list-hidden for more) |
| --version - Display the version of this program |
| |
| |
| When the desired code formatting style is different from the available options, |
| the style can be customized using the ``-style="{key: value, ...}"`` option or |
| by putting your style configuration in the ``.clang-format`` or ``_clang-format`` |
| file in your project's directory and using ``clang-format -style=file``. |
| |
| An easy way to create the ``.clang-format`` file is: |
| |
| .. code-block:: console |
| |
| clang-format -style=llvm -dump-config > .clang-format |
| |
| Available style options are described in :doc:`ClangFormatStyleOptions`. |
| |
| |
| Vim Integration |
| =============== |
| |
| There is an integration for :program:`vim` which lets you run the |
| :program:`clang-format` standalone tool on your current buffer, optionally |
| selecting regions to reformat. The integration has the form of a `python`-file |
| which can be found under `clang/tools/clang-format/clang-format.py`. |
| |
| This can be integrated by adding the following to your `.vimrc`: |
| |
| .. code-block:: vim |
| |
| map <C-K> :pyf <path-to-this-file>/clang-format.py<cr> |
| imap <C-K> <c-o>:pyf <path-to-this-file>/clang-format.py<cr> |
| |
| The first line enables :program:`clang-format` for NORMAL and VISUAL mode, the |
| second line adds support for INSERT mode. Change "C-K" to another binding if |
| you need :program:`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. |
| |
| An alternative option is to format changes when saving a file and thus to |
| have a zero-effort integration into the coding workflow. To do this, add this to |
| your `.vimrc`: |
| |
| .. code-block:: vim |
| |
| function! Formatonsave() |
| let l:formatdiff = 1 |
| pyf ~/llvm/tools/clang/tools/clang-format/clang-format.py |
| endfunction |
| autocmd BufWritePre *.h,*.cc,*.cpp call Formatonsave() |
| |
| |
| Emacs Integration |
| ================= |
| |
| Similar to the integration for :program:`vim`, there is an integration for |
| :program:`emacs`. It can be found at `clang/tools/clang-format/clang-format.el` |
| and used by adding this to your `.emacs`: |
| |
| .. code-block:: common-lisp |
| |
| (load "<path-to-clang>/tools/clang-format/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. |
| |
| |
| BBEdit Integration |
| ================== |
| |
| :program:`clang-format` cannot be used as a text filter with BBEdit, but works |
| well via a script. The AppleScript to do this integration can be found at |
| `clang/tools/clang-format/clang-format-bbedit.applescript`; place a copy in |
| `~/Library/Application Support/BBEdit/Scripts`, and edit the path within it to |
| point to your local copy of :program:`clang-format`. |
| |
| With this integration you can select the script from the Script menu and |
| :program:`clang-format` will format the selection. Note that you can rename the |
| menu item by renaming the script, and can assign the menu item a keyboard |
| shortcut in the BBEdit preferences, under Menus & Shortcuts. |
| |
| |
| CLion Integration |
| ================= |
| |
| :program:`clang-format` is integrated into `CLion <https://www.jetbrains |
| .com/clion/>`_ as an alternative code formatter. CLion turns it on |
| automatically when there is a ``.clang-format`` file under the project root. |
| Code style rules are applied as you type, including indentation, |
| auto-completion, code generation, and refactorings. |
| |
| :program:`clang-format` can also be enabled without a ``.clang-format`` file. |
| In this case, CLion prompts you to create one based on the current IDE settings |
| or the default LLVM style. |
| |
| |
| Visual Studio Integration |
| ========================= |
| |
| Download the latest Visual Studio extension from the `alpha build site |
| <https://llvm.org/builds/>`_. The default key-binding is Ctrl-R,Ctrl-F. |
| |
| |
| Visual Studio Code Integration |
| ============================== |
| |
| Get the latest Visual Studio Code extension from the `Visual Studio Marketplace <https://marketplace.visualstudio.com/items?itemName=xaver.clang-format>`_. The default key-binding is Alt-Shift-F. |
| |
| |
| Script for patch reformatting |
| ============================= |
| |
| The python script `clang/tools/clang-format/clang-format-diff.py` parses the |
| output of a unified diff and reformats all contained lines with |
| :program:`clang-format`. |
| |
| .. code-block:: console |
| |
| usage: clang-format-diff.py [-h] [-i] [-p NUM] [-regex PATTERN] [-style STYLE] |
| |
| Reformat changed lines in diff. Without -i option just output the diff that |
| would be introduced. |
| |
| optional arguments: |
| -h, --help show this help message and exit |
| -i apply edits to files instead of displaying a diff |
| -p NUM strip the smallest prefix containing P slashes |
| -regex PATTERN custom pattern selecting file paths to reformat |
| -style STYLE formatting style to apply (LLVM, Google, Chromium, Mozilla, |
| WebKit) |
| |
| So to reformat all the lines in the latest :program:`git` commit, just do: |
| |
| .. code-block:: console |
| |
| git diff -U0 --no-color HEAD^ | clang-format-diff.py -i -p1 |
| |
| With Mercurial/:program:`hg`: |
| |
| .. code-block:: console |
| |
| hg diff -U0 --color=never | clang-format-diff.py -i -p1 |
| |
| In an SVN client, you can do: |
| |
| .. code-block:: console |
| |
| svn diff --diff-cmd=diff -x -U0 | clang-format-diff.py -i |
| |
| The option `-U0` will create a diff without context lines (the script would format |
| those as well). |
| |
| These commands use the file paths shown in the diff output |
| so they will only work from the root of the repository. |
| |
| Current State of Clang Format for LLVM |
| ====================================== |
| |
| The following table :doc:`ClangFormattedStatus` shows the current status of clang-formatting for the entire LLVM source tree. |