emacs-cquery is a client for cquery, a low-latency language server supporting multi-million line C++ code-bases, powered by libclang.

It leverages lsp-mode, but also provides some cquery extensions to LSP:

• semantic highlighting
• inactive region (e.g. a #if false region)
• cross references: $cquery/base $cquery/callers $cquery/derived $cquery/vars

More on https://github.com/cquery-project/cquery/wiki/Emacs

(require 'cquery)
(setq cquery-executable "/path/to/cquery/build/release/bin/cquery")
;; (setq cquery-executable "/path/to/cquery-install-prefix/bin/cquery")

To enable comments and use Message Pack for cache files (which are stored in cacheDirectory):

(setq cquery-extra-init-params '(:index (:comments 2) :cacheFormat "msgpack"))

Refer to https://github.com/jacobdufault/cquery/wiki/Emacs for details.

$cquery/callHierarchy (caller hierarchy and callee hierarchy)

MIT