OutOfMemoryError since 4.9.0

[xuwei-k]

xuwei-k/scalameta-memory-issue-3650@765dccb

reproduce code

package example

import scala.meta._
import scala.meta.inputs.Input
import scala.meta.parsers.Parse
import scala.meta.prettyprinters._
import scala.meta.transversers._
import scala.jdk.StreamConverters._
import java.io.File

object Main {
  def main(args: Array[String]): Unit = {
    // parse many scala code
    // e.g. https://github.com/scala/scala 2.13.x branch
    java.nio.file.Files.find(
      new File("scala", "src").toPath,
      100,
      (p, _) => p.toFile.getName.endsWith(".scala") && (p.toFile.getName != "Singleton.scala")
    ).toScala(List).map { f =>
      val tree = implicitly[Parse[Source]].apply(Input.File(f), scala.meta.dialects.Scala213Source3).get
      tree.traverse { a => () }
      tree
    }
  }
}

VisualVM results in my local Mac

• https://visualvm.github.io/

4.8.15

4.9.0

GitHub Actions result

• https://github.com/xuwei-k/scalameta-memory-issue-3650/actions/runs/8305399108

4.8.15

[info] running (fork) example.Main 
[success] Total time: 18 s, completed Mar 16, 2024, 4:43:48 AM

4.9.0

[info] running (fork) example.Main 
[error] Exception in thread "main" java.lang.OutOfMemoryError: Java heap space

note

generated too many TrieMap. maybe f840d2e 🤔

[xuwei-k]

scalafmt gc log

scalafmt 3.8.0( scalameta 4.9.0)

scalafmt 3.7.17( scalameta 4.8.14)

[kitbellew]

this seems like a strange oversight to me: f840d2e#diff-328bbe30c12809ccabef99878be748a69632e114e66ba67003f7be8d3b77d1e1R64

not sure if lazy vals can contribute.

[kitbellew]

@xuwei-k is it possible to verify whether this problem is present in 4.9.3, please?

[xuwei-k]

I have confirmed not present in 4.9.3. Thanks! 👍