Clang MapReduce -- Automatic C++ Refactoring at Google Scale

Google has over 100 million lines of code, and our biggest programming language is C . We have a single, shared codebase developed primarily on mainline. We build every binary and all of its libraries from scratch every time, allowing us to incrementally evolve APIs and libraries over time. The entire development process is extremely incremental in nature, and even API-breaking changes are a regular occurrence. However, for core libraries used throughout the codebase, this development model is a huge chall