GetFileAttributesW is the main slowdown of CMake on Windows
During my performance investigations of CMake on Windows I find that calls to GetFileAttributesW
seem to be the main reason of CMakes slow runtime on Windows when compared to that on Linux. I could already remove some GetFileAttributesW
calls in !6849 (closed), but there are still plenty of calls left. I hope that I can raise awareness concerning this problem and that you maybe have some ideas how to eliminate these calls.
Some profiling results
During profiling of commit d282ca55 when configuring Ninja on llvms codebase I observe the following: