What is scalac-profiling?
scalac-profiling is a compilation profiling tool for Scala 2 projects
which aims to help you better understand what is slowing down compilation in your project.
As of the 1.1.2 version, it's built for Scala 2.12 and 2.13.
When to use scalac-profiling?
Using implicits and macros can significantly increase compilation time,
based on their usage and your codebase organization. Suppose your project
heavily depends on automatic code generation tools powered with macros,
like type-classes derivation, while it's a super powerful and user-friendly technology,
it's likely to materialize implicits for the same type many times across the project
resulting in excessive compilation time. Given all of that, although the scalac-profiling
can be used for general compilation analysis, it is best for chasing down bottlenecks
with a focus on implicit searches and macro expansions.
Why scalac-profiling?
With scalac-profiling, you can easily generate advantageous flamegraphs
that provide next-level profiling of compilation times. Explore the following flamegraph
of the implicit searches in the Scala Steward project
we've built by literally adding 5 LoC to the build file and running one script
from the FlameGraph project. Note that the following graph is clickable.
Maintenance status
This tool originated at the Scala Center in 2017-2018 as the result of the proposal SCP-10, submitted by a corporate member of the board. The Center is seeking new corporate members to fund activities such as these, to benefit the entire Scala community.
The scalac-profiling is now community-maintained, with maintenance overseen by the Center.
We invite interested users to participate and submit further improvements.