You can use YouCompleteMe to provide error checking, completion and source navigation within the Fuchsia tree.
YouCompleteMe works natively with Vim but it can also be integrated with other editors through ycmd.
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.
(compiling on gLinux, even if editing over SSHFS on MacOS) Ignore the above. Search the Google intranet for “YouCompleteMe” for installation instructions.
The general Vim Fuchsia instructions will do this automatically.
You'll need to set the ycmd config option global_ycm_extra_conf to point to ${FUCHSIA_DIR}/scripts/youcompleteme/ycm_extra_conf.py. Note you may need to manually replace ${FUCHSIA_DIR} with the correct path.