ccls
C/C++/ObjC language server supporting cross references & hierarchies
C/C++/ObjC language server supporting cross-references, hierarchies, completion, and semantic highlighting. It has a global view of the code base and supports a lot of cross-reference features, see wiki/FAQ. It starts indexing the whole project (including subprojects if exist) parallelly when you open the first file, while the main thread can serve requests before the indexing is complete.