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;).