ClangTidy

Clang-Tidy is a clang-based C/C++ linter and static analysis tool that is part of the LLVM project. It analyzes source code using Clang's libTooling and AST matchers to find bugs, coding style violations, and potential performance issues, and it can propose automatic fixes (fix-its).

The checks are grouped into modules such as readability, modernize, performance, portability, bugprone, and misc, and can be enabled or disabled selectively.

Clang-Tidy operates on a compilation database, typically compile_commands.json, and can read an inline .clang-tidy configuration file or be driven entirely by command-line options. It supports the -checks flag to enable or disable checks, -warnings-as-errors to treat certain checks as failures, and -fix to emit edits directly to the source. It can be run as a standalone tool or integrated into build systems (for example via a CMake script) and into continuous integration pipelines. It also supports diff generation with clang-tidy-diff and can be used with -format to apply formatting changes.

The checks are implemented as plugins within the clang-tidy framework and rely on Clang's AST to reason about code semantics. While powerful, some checks may produce false positives or require accurate compilation databases; developers should review fixes before committing. Clang-Tidy is commonly used to enforce coding standards, modernize legacy code, and improve code quality across large C++ codebases.