5.3 Clang-Tidy’s internal design
Clang-Tidy is built on top of Clang. At its core, Clang-Tidy leverages Clang’s ability to parse and analyze source code into an AST. Each check in Clang-Tidy essentially involves defining patterns or conditions to match against this AST. When a match is found, a diagnostic can be raised, and in many cases, an automatic fix can be suggested. The tool operates on the basis of individual ”checks” that target specific issues or coding styles. Checks are implemented as plugins, making Clang-Tidy extensible. The ASTMatchers library facilitates writing these checks by providing a domain-specific language to query the AST; see Section 3.5, AST matchers and the official documentation [16] for more info. This ensures that checks are both concise and expressive. Clang-Tidy also has support for analyzing the code base using a compilation database, which provides context such as compile flags (see Chapter 9, Appendix 1: Compilation...
