YouCompleteMe integration

YouCompleteMe is a semantic code-completion engine. YouCompleteMe works natively with Vim but it can also be integrated with other editors through ycmd.

Install YouCompleteMe in your editor

{% dynamic if user.is_googler %}

[Googlers only] gLinux

(This applies to anyone compiling on gLinux, even if editing over SSHFS on MacOS) See the Google intranet specific instructions go/ycm.

You‘ll also need to setup ${FUCHSIA_DIR}/scripts/youcompleteme/default_settings.json as the default settings path in your editor, in order to disable the internal use_clangd flag. If you want to use clangd, you can additionally edit that file to set use_clangd to 1, and clang_binary_path to ${FUCHSIA_DIR}/prebuilt/third_party/clang/${HOST_PLATFORM}/bin/clangd. Remember that in that case, you’ll need to build a compilation database with fx compdb.

{% dynamic else %}

See the installation guide.

Note: Installing YCM on MacOS with Homebrew is not recommended because of library compatibility errors. Use the official installation guide instead.

{% dynamic endif %}

Generate compilation database

YouCompleteMe (and other tools like clang-tidy) require a JSON compilation database that specifies how each file is compiled. This database is normally stored in a file called compile_commands.json. You can build a compilation database with fx compdb, or fx -i compdb if you want it rebuilt automatically as you edit files.

If this database is not present, then Vim can be configured to fall back to the configuration in /scripts/youcompleteme/ See Vim configuration for how to set this up.

Use it

YouCompleteMe will use compile_commands.json to do code completion and find symbol definitions/declarations. See your editor's YouCompleteMe docs for details. The editor should pick up compile_commands.json file automatically.

See Vim setup for instructions on configuring Vim for Fuchsia development.

Other editors (ycmd)

You'll need to set the ycmd config option global_ycm_extra_conf to point to ${FUCHSIA_DIR}/scripts/youcompleteme/ Note you may need to manually replace ${FUCHSIA_DIR} with the correct path.

Alternatively, you can create a symbolic link to let YCM automatically find the config for any fuchsia repository:

ln -s $FUCHSIA_DIR/scripts/youcompleteme/ $FUCHSIA_DIR/