Sourcetrail is a cross-platform visual source explorer based on Clang libTooling
by Eberhard Gräther
From the article:
Sourcetrail 2018.3 brings new usability features for faster source code exploration. Users can continue to browse while reindexing in the background. A graph legend and new node actions have been added to the graph visualization. The code view was extended with a local reference navigation. Project setup now supports Sonargraph and Code::Blocks project import.