Weggli

Semantic search tool for C and C++ codebases

weggli is a fast and robust semantic search tool for C and C++ codebases. It is designed to help security researchers identify interesting functionality in large codebases.

weggli performs pattern matching on Abstract Syntax Trees based on user provided queries. Its query language resembles C and C++ code, making it easy to turn interesting code patterns into queries.

weggli is inspired by great tools like Semgrep, Coccinelle, joern and CodeQL, but makes some different design decisions

• C++ support weggli has first class support for modern C++ constructs, such as lambda expressions, range-based for loops and constexprs.
• Minimal setup weggli should work out-of-the box against most software you will encounter. weggli does not require the ability to build the software and can work with incomplete sources or missing dependencies.
• Interactive weggli is designed for interactive usage and fast query performance. Most of the time, a weggli query will be faster than a grep search. The goal is to enable an interactive workflow where quick switching between code review and query creation/improvement is possible.
• Greedy weggli’s pattern matching is designed to find as many useful matches as possible for a specific query. While this increases the risk of false positives it simplifies query creation. For example, the query $x = 10; will match both assignment expressions foo = 10; and declarations int bar = 10;.