clangd is a clang-based language server. It brings IDE features (e.g. diagnostics, code completion, code navigations) to your editor.

Getting clangd

See instructions.

Googlers: clangd has been installed on your glinux by default, just use /usr/bin/clangd.

Alternative: use the following command to build clangd from LLVM source, and you will get the binary at out/Release/tools/clang/third_party/llvm/build/bin/clangd.

tools/clang/scripts/ --fetch out/Release clangd

Setting Up

  1. Build chrome normally. This step is required to make sure we have all generated files.
ninja -C out/Release chrome
  1. Generate the compilation database, clangd needs it to know how to build a source file.
tools/clang/scripts/ -p out/Release > compile_commands.json

Note: the compilation database is not re-generated automatically, you'd need to regenerate it manually when you have new files checked in.

  1. Use clangd in your favourite editor, see detailed instructions.


By default, clangd only knows the files you are currently editing. To provide project-wide code navigations (e.g. find references), clangd neesds a project-wide index.

You can pass an experimental --background-index command line argument to clangd, clangd will incrementally build an index of Chromium in the background. Note: the first index time may take hours (for reference, it took 2~3 hours on a 48-core, 64GB machine).

A full index of Chromium (including v8, blink) takes ~550 MB disk space and ~2.7 GB memory in clangd.


If you have any questions, reach out to