Welcome to joern’s documentation!

Joern is a platform for robust analysis of C/C++ code developed by Fabian Yamaguchi at the Computer Security Group of the University of Goettingen. It generates code property graphs, a novel graph representation that exposes the code’s syntax, control-flow, data-flow and type information in a joint data structure. Code property graphs are stored in a Neo4J graph database. This allows code to be mined using search queries formulated in the graph traversal language Gremlin.

  • Fuzzy Parsing. Joern employs a fuzzy parser, allowing code to be imported even if a working build environment cannot be supplied.
  • Code Property Graphs. Joern creates code property graphs from the fuzzy parser output and makes and stores them in a Neo4J graph database. For background information on code property graphs, we strongly encourage you to read our paper on the topic.
  • Extensible Query Language. Based on the graph traversal language Gremlin, Joern offers an extensible query language based on user-defined Gremlin steps that encode common traversals in the code property graph. These can be combined to create search queries easily.

This is joern’s official documentation. It covers its installation and configuration, discusses how code can be imported and retrieved from the database and gives an overview of the database contents.