Editor integration for Zircon

YouCompleteMe

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

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.

gLinux (Googlers only)

(This applies to anyone compiling on gLinux, even if editing over SSHFS on MacOS) Ignore the above. Search the Google intranet for “YouCompleteMe” for installation instructions.

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. There are multiple ways to generate this database for Zircon.

compiledb-generator

compiledb-generator is the recommended way to generate a compilation database. It works by running make in no-op mode and parsing the output. Thus it may be less accurate than bear, but it should be able to produce a complete database very quickly and without requiring a clean build.

To use it, download it from GitHub and run (ensure that compiledb is in your PATH)

cd "${ZIRCON_DIR}"
compiledb -o compile_commands.json -n make <make args>

Bear

Bear intercepts exec(3) calls made during a build and scrapes commandlines that look like C/C++ compiler invocations. Thus it is guaranteed to accurately capture the commands used during compilation. However it can't incrementally maintain a compilation database, so it requires performing a clean build.

Install Bear

You can try using your system‘s package manager (apt-get, brew) to install Bear, but you will need version 2.2.1 or later to match the compiler names that Zircon uses. Both homebrew’s and Debian testing's versions are sufficiently new. You can also fall back to installing it from GitHub.

Invoke Bear on the Zircon build system

You‘ll need to do this whenever the sources or makefiles change in a way that affects includes or types, or when you add/delete/move files, though it doesn’t hurt to use a stale database.

As easy as:

cd "${ZIRCON_DIR}"
make clean
bear make -j$(getconf _NPROCESSORS_ONLN)

This will create a compile_commands.json file in the local directory.

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.

It should pick up the json file automatically. If you want to move it out of the zircon tree, you can move the file to its parent directory.