How can I diagnose performance issues in CLion using measurement tools?

When working with CLion, users may observe slowdowns during indexing or builds. What systematic approach can be taken to measure and identify bottlenecks, such as using built‑in profilers, external tools like perf or Valgrind, or CLion’s own performance tests? Please outline the steps, what metrics to collect, how to verify findings, and how to roll back changes if needed.