Installation · scalac-profiling

Pick the right version

Scala series	Supported versions	`scalac-profiling`
2.12.x	2.12.20, 2.12.19, 2.12.18	`1.2.0`
2.13.x	2.13.17, 2.13.16, 2.13.15, 2.13.14	`1.2.0`

Add the dependency

Add the scalac compiler plugin into your build:

addCompilerPlugin("ch.epfl.scala" %% "scalac-profiling" % "1.2.0" cross CrossVersion.full)

Also, it's required to enable compiler statistics — for Scala 2.13 the needed compiler flag is -Vstatistics, and for Scala 2.12 is -Ystatistics.

For example, for the SBT build tool, add the following settings to build.sbt:

+ inThisBuild(
+   List(
+     addCompilerPlugin("ch.epfl.scala" %% "scalac-profiling" % "1.2.0" cross CrossVersion.full),
+     ThisBuild / scalacOptions += "-Vstatistics",
+   )
+ )

You can also use project-scoped settings if you want to profile a particular project:

lazy val myproject = project
  .settings(
+   addCompilerPlugin("ch.epfl.scala" %% "scalac-profiling" % "1.2.0" cross CrossVersion.full),
+   ThisBuild / scalacOptions += "-Vstatistics",
  )

Extend the configuration

There are several compiler plugin options to enable to enrichment of analysis capabilities. All the following options are prepended by the -P:scalac-profiling:.

Name	Description
`generate-global-flamegraph`	Creates a global flamegraph of implicit searches for all compilation units. Use the `-P:scalac-profiling:cross-target` option to manage the target directory for the resulting flamegraph file, otherwise, the SBT target directory will be picked.
`generate-macro-flamegraph`	Generate a flamegraph for macro expansions. The flamegraph for implicit searches is enabled by default.
`generate-profiledb`	Generate profiledb.
`print-failed-implicit-macro-candidates`	Print trees of all failed implicit searches that triggered a macro expansion.
`print-search-result`	Print the result retrieved by an implicit search. Example: `-P:scalac-profiling:print-search-result:$MACRO_ID`.
`show-concrete-implicit-tparams`	Use more concrete type parameters in the implicit search flamegraph. Note that it may change the shape of the flamegraph.
`show-profiles`	Show implicit searches and macro expansions by type and call-site.
`sourceroot`	Tell the plugin what is the source directory of the project. Example: `-P:scalac-profiling:sourceroot:$PROJECT_BASE_DIR`.
`cross-target`	Tell the plugin what is the cross target directory of the project. Example: `-P:scalac-profiling:cross-target:$PROJECT_TARGET`.