protobuf/ci/README.md

This directory contains CI-specific tooling.

Clang wrappers

CMake allows for compiler wrappers to be injected such as ccache, which intercepts compiler calls and short-circuits on cache-hits. This can be done by specifying CMAKE_C_COMPILER_LAUNCHER and CMAKE_CXX_COMPILER_LAUNCHER during CMake's configure step. Unfortunately, X-Code doesn't provide anything like this, so we use basic wrapper scripts to invoke ccache + clang.

Bazelrc files

In order to allow platform-specific .bazelrc flags during testing, we keep 3 different versions here along with a shared common.bazelrc that they all include. Our GHA infrastructure will select the appropriate file for any test and overwrite the default .bazelrc in our workspace, which is intended for development only.