Glean: C++ Code Indexing at Meta
summary
Glean is a Meta-built indexing platform that uses Clang ASTs, RocksDB and a small query language (Angle) to store deduplicated facts from huge C++ trees plus Buck2 and Thrift artifacts, collapsing thousands of header occurrences into single facts and powering go‑to‑definition, cross‑repo Thrift→C++ jumps and incremental rebuilds. It records macro spellings vs expansions and separate name locations, derives a language‑neutral code‑markup layer, and exposes queries as stored predicates so Angle schema + Thrift facts drive fast navigation and analytics.
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chapters (17)
- 0:00Introduction to Glean
- 6:49Architecture overview
- 11:00Schema design challenges
- 19:14Macro location types
- 22:19Introducing Angle
- 33:03Deriving code markup
- 40:59C++ macro navigation
- 47:14Demo of macro navigation
- 49:20Template instantiation indexing
- 51:30Handling local edits
- 54:44Adopting Glean in projects
- 57:11Incremental indexing
- 1:01:31Cross-repository navigation
- 1:06:10Future improvements
- 1:11:31Open sourcing LSP integration
- 1:19:40Supporting multiple languages
- 1:21:50Closing and Q&A
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